5-Ten Test Tube Mystery

Standardization and titration is a quantitative technique that can produce accurate and precise results when done carefully. It involves standardizing a sodium hydroxide (NaOH) solution by performing multiple titrations of a primary standard potassium hydrogen phthalate (KHP) of known molarity. This allows the determination of an unknown concentration of acetic acid by titrating samples with the standardized NaOH solution. Proper experimental procedure and tips are provided to complete the standardization and acetic acid titrations.

Lab report writing

vee177

This document provides guidance on writing an eighth grade science lab report on how temperature affects the rate of a chemical reaction. It recommends writing a focused research question that specifies the independent variable (temperature from 40 to 80 degrees Celsius) and dependent variable (mass of reaction mixture in grams). The hypothesis should state that as temperature increases, the mass will decrease due to one of the products escaping as a gas. The method section describes the controlled variables and step-by-step process for conducting trials at different temperatures, recording data, and presenting it in a table.

Rates of reaction

rudi_z

Here are the effects on the rate of reaction of changing each condition: - If the concentration of acid is increased, the rate of reaction will increase. This is because there will be more reactant particles per unit volume, resulting in more frequent collisions between reactants. - If calcium carbonate powder is used instead of small pieces, the rate of reaction will increase. This is because powder has a larger surface area, allowing for more reactant particles at the interface where the reaction occurs. - If the volume of acid is increased, the rate of reaction will initially increase but then level off. This is because there will be more reactant particles initially, but the reaction will use them up over time. - If the

Acid base

Janet Krahenbuhl

The document describes the materials and methods used in a titration lab experiment. Materials included a pH probe, buret, beakers, stir plate, balance, pipette, and NaOH and KHP solutions. The method involved standardizing a NaOH solution by titrating it into KHP and measuring the pH, then using the standardized NaOH to titrate two unknown acids and calculate their identities based on titration curves and pKa values.

TOPIC 5. RATE OF REACTION-LAB

projecteciencies

The document discusses several experiments on factors that affect the rate of chemical reactions: 1. Particle size - Comparing the reaction of dilute HCl with large vs. small marble chips to see how particle size impacts the reaction rate. Smaller particles react faster due to a greater surface area. 2. Catalyst - Adding manganese dioxide speeds up the decomposition of hydrogen peroxide into oxygen and water, showing how a catalyst increases the reaction rate without being used up in the reaction. 3. Temperature - Measuring the time it takes for tablets to dissolve in hot, room temperature, and cold water, demonstrating that higher temperatures increase molecular motion and collision frequency, speeding up reactions.

Rate of reaction temperature

mmandylou

This document outlines an experiment to determine how temperature affects the rate of reaction between sodium thiosulfate and hydrochloric acid. It describes the independent variable as the temperature of the hydrochloric acid ranging from 0°C to 80°C. The dependent variable is the time for a cross drawn on paper to become invisible when placed behind a test tube containing the reaction. The method involves timing how long it takes for the cross to disappear at each temperature, with results recorded in a table. The conclusion states that higher temperatures led to faster reaction times, supporting the particle collision theory that increasing temperature causes particles to move faster and collide more frequently.

Rate of Reaction

M BR

The document outlines the procedures for 5 experiments that investigate factors that affect the rate of chemical reactions. The experiments will study how: 1) The size of calcium carbonate affects the rate of its reaction with hydrochloric acid. 2) The concentration of sodium thiosulphate solution affects the rate of its reaction with sulfuric acid. 3) The temperature of sodium thiosulphate solution affects its reaction rate with sulfuric acid. 4) The presence of manganese(IV) oxide affects the decomposition rate of hydrogen peroxide. 5) The presence of copper(II) sulfate affects the reaction rate between zinc and sulfuric acid.

This document summarizes an experiment to determine the enthalpy of decomposition of hydrogen peroxide in aqueous solution. The experiment involves first calibrating an isobaric calorimeter to determine its heat capacity. Then hydrogen peroxide solution is added to the calorimeter and manganese dioxide is used to catalyze the decomposition reaction. Temperature readings are taken before and after the reaction to determine the temperature change. The concentration of hydrogen peroxide is determined by titration and used to calculate moles reacted. From this, the enthalpy of decomposition is calculated to be -96 kJ/mole.

Factors affecting rate of reaction (recovered)

Siti Alias

The document discusses how several factors affect the rate of chemical reactions according to collision theory: 1. Increasing the surface area of reactants by decreasing their size increases the rate of reaction by increasing collision frequency. 2. Higher concentrations increase collision frequency by providing more particles in a given volume, likewise increasing the reaction rate. 3. Higher temperatures cause reactants to move faster and collide more frequently, also increasing the reaction rate. 4. Catalysts can lower the activation energy for a reaction, increasing the frequency of effective collisions and thereby accelerating the reaction. 5. For gas reactions, higher pressures compress the gas, providing more particles per volume and thus more collisions and a faster reaction.

Elly lee effect of temperature on reaction rate

janlee97

Elly Lee conducted an experiment to observe the effect of temperature on reaction rates. Zinc was reacted with HCl at different temperatures and the reaction times were recorded. The results showed that reaction times decreased as temperature increased, with the fastest reaction occurring at 49.9°C and the slowest at 6.1°C. The type of gas produced also changed with temperature. This supports the hypothesis that increasing temperature increases reaction rates.

Final Report

Shripal Shah

1. Dendrimer-encapsulated gold nanoparticles were used to catalyze the reduction of 4-nitrophenol to 4-aminophenol at 40°C. 2. Five reaction conditions were tested with varying concentrations of 4-nitrophenol. Rate constants for the reactions were calculated and it was expected that the rate would decrease with increasing 4-nitrophenol concentration. 3. However, the results showed that the rate constants actually increased as the 4-nitrophenol concentration increased, with the highest rate seen at the highest concentration tested of 4M 4-nitrophenol. This trend was unexpected and suggests possible errors in the experiment.

Heat of Reaction

M BR

This document outlines the procedures for four experiments to determine heat of reaction: heat of precipitation by mixing silver nitrate and sodium chloride solutions; heat of displacement by adding zinc to copper nitrate; heat of neutralization by mixing hydrochloric acid and sodium hydroxide; and heat of combustion by burning butanol to heat water. It records the initial and highest temperatures of the reactions and solutions, as well as the mass of butanol used.

Absolute isotopic scale for deuterium analysis of natural waters

Mahbubul Hassan

This document defines an absolute isotopic scale for deuterium analysis of natural waters based on measurements of two reference standards - Standard Mean Ocean Water (SMOW) and Standard Light Antarctic Precipitation (SLAP). The absolute D/H ratios were measured through mass spectrometric comparison with calibration mixtures prepared in the laboratory. The results obtained are: 1) The absolute D/H ratio of SMOW is 155.76 ± 0.05 x 10-6. 2) The absolute D/H ratio of SLAP is 89.02 ± 0.05 x 10-6. 3) The δD value of SLAP relative to SMOW is -428.50 ±

Determination equilibrium constant

This document describes an experiment to determine the equilibrium constant (Kc) for the reaction of iron(III) ions (Fe3+) with thiocyanate ions (SCN-) to form the deep red colored iron(III) thiocyanate complex ion (FeSCN2+). The experiment involves: 1. Constructing a calibration curve by measuring the absorbance of standard FeSCN2+ solutions and determining the molar absorptivity. 2. Reacting solutions with varying initial concentrations of Fe3+ and SCN- and measuring the equilibrium concentration of FeSCN2+ using the calibration curve. 3. Calculating Kc for each reaction using the determined equilibrium concentrations

Chemical reactions p pt

mmandylou

This experiment investigated how the concentration of hydrochloric acid affects the reaction time of magnesium ribbon. Five concentrations of HCl from 100% to 20% were tested, and the time taken for the magnesium ribbon to completely disappear was recorded. The results showed that higher concentrations of HCl led to faster reaction times, supporting the particle collision theory that higher concentrations provide more opportunities for effective particle collisions between HCl and magnesium.

Investigate the effect of temperature on amylase activity

lanceqwerty

The document describes an experiment to investigate the effect of temperature on amylase activity. The aim is to determine the reaction rate of amylase and starch solutions at different temperatures (0°C, room temperature, 40°C, 60°C, 80°C). It is hypothesized that the reaction rate will initially increase with temperature until an optimal temperature is reached, above which the enzyme will denature and the rate will decrease. The method involves mixing amylase and starch solutions at the various temperatures and recording the time taken for the blue-black color from iodine solution to disappear. However, the results showed no color change, suggesting a failure of the experimental method.

Ch5 z5e gases

blachman

The document summarizes key gas laws including Boyle's law, Charles' law, Avogadro's law, Dalton's law of partial pressures, and the ideal gas law. It provides examples of using these laws to calculate volume, pressure, temperature, moles, and mass in gas reactions and mixtures. Key relationships covered are that pressure and volume are inversely related at constant temperature (Boyle's law), volume and temperature are directly related at constant pressure (Charles' law), and volume and moles are directly related at constant temperature and pressure (Avogadro's law).

Borax

This experiment aims to determine the thermodynamic parameters (ΔG°, ΔH°, ΔS°) for the dissolution of borax into borate ions in water at two temperatures. Students will prepare saturated borax solutions at room temperature and in an ice bath. They will titrate aliquots of the solutions with HCl to determine the borate ion concentration and calculate the solubility product (Ksp) at each temperature. Using the Ksp values and equations relating ΔG°, ΔH°, and ΔS° to temperature and Ksp, students can determine the thermodynamic parameters for this dissolution reaction. This will provide insight into whether the reaction is spontaneous and the roles of entropy and enthalpy.

Karl Fischer Titration

Niloy Hassan

Handling Difficult Samples in Karl Fischer Analysis

Metrohm USA

Effect of variation in temperature & pH levels on the activity of salivary am...

Nidhi Sharma

This document describes an experiment to study the effects of temperature and pH levels on the activity of salivary amylase on starch. For the temperature experiment, starch solution was placed in test tubes at 5°C, 37°C and 50°C with saliva added. The test tube at 37°C reached the point where iodine no longer detected starch the quickest, showing optimal enzyme activity at body temperature. For the pH experiment, starch solution was adjusted to pH 5, 6.8 and 8 with saliva added. Activity was only observed at pH 6.8, as the enzyme does not function in acidic or alkaline environments.

Biochemistry lab reporttt

Indira Oez

This document is a lab report that examines the effect of substrate concentration on enzyme kinetics. The introduction provides background on how enzyme concentration and reaction order affect the reaction rate. Specifically, it explains that a zero-order reaction rate is independent of substrate concentration. The methods section describes the experiment, which used potato as an enzyme source to catalyze the breakdown of hydrogen peroxide at different substrate concentrations. Results are presented in a graph, and the discussion section analyzes how enzymes function as catalysts to speed chemical reactions.

11 kf-theory jntu pharmacy

Dr. Suman Pattanayak

This document discusses Karl Fischer titration methods for determining water content. It covers the KF reaction, volumetric and coulometric titration techniques, endpoint indication, drift correction, parameters, and KF instrumentation. Volumetric titration uses an iodine titrant while coulometric generates iodine via electrolysis. Both methods indicate the endpoint potentiometrically and use drift as a secondary check. Parameters like dynamics, stop criteria, and currents must be optimized. Common KF titration instruments include the Titrino, Titrando, Coulometer, and oven systems.

Dc lab 5

ykhan60

This document describes an experiment to determine the efficiency of a continuous plate distillation column. It provides background on distillation column design and efficiency calculations using concepts like theoretical plates, reflux ratio, and Fenske's method. The experiment involves running a methanol-water mixture through a distillation column at total reflux to establish equilibrium. Samples are taken from the overhead and their compositions are measured using a refractometer and calibration curve. The number of theoretical plates is then calculated using the compositions and Fenske's method. This is compared to the actual number of plates in the column to determine the efficiency. Key steps include establishing a calibration curve, collecting samples at various reflux rates, measuring compositions, and performing efficiency calculations.

Experiment 1 performing a precipitation reactionexperiment in

modi11

1. In this experiment, students will observe the precipitation reaction between sodium fluoride (NaF) and calcium acetate [(Ca(C2H3O2)2)] to form calcium fluoride precipitate. 2. The procedure involves adding 10 mL of NaF to a test tube, followed by 3 mL of 1 M calcium acetate solution. Students are instructed to observe and photograph the reaction mixture at various time intervals as a white precipitate forms. 3. The purpose is for students to observe a precipitation reaction and record their observations of the formation of calcium fluoride precipitate over time.

Unit 6 Water Content Determination and Moisture analysis

Malou Mojares

Descaling procedure

AbhishekSingh3693

The document outlines a descaling procedure for industrial equipment that involves making a 6-7% sulphamic acid solution with corrosion inhibitors, circulating the heated solution through the equipment, monitoring the solution percentage and sampling every 30 minutes, adding more sulphamic acid as needed to maintain the percentage as scaling is removed, stopping circulation when the percentage no longer decreases, flushing with fresh water, circulating alkaline water for 2 hours, and finally checking equipment parameters and heat transfer efficiency after completion.

Precipitation react 1

pinillafelisa

This document describes a lab experiment on precipitation reactions. Students will observe precipitation reactions by mixing aqueous solutions of cations and anions in test tubes. They will identify which two cations form the most precipitates. The materials needed are listed. The procedure involves placing solutions in test tubes and observing any color changes or precipitate formation. Examples of double displacement reactions that form precipitates are provided, such as the reaction of Pb(NO3)2 and NaCl forming an insoluble PbCl2 precipitate. Safety precautions are emphasized.

Sample lab

emchitt

The document describes an acid-base titration lab experiment where students will: 1) Titrate a measured volume of HCl of unknown concentration with a NaOH solution of known concentration to determine the concentration of HCl. 2) Calculate the number of moles of NaOH used in each trial and determine the concentration of HCl from the reaction. 3) Calculate their percent error compared to the accepted HCl concentration value.

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Heat of Reaction

M BR

Absolute isotopic scale for deuterium analysis of natural waters

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Chemical reactions p pt

mmandylou

Investigate the effect of temperature on amylase activity

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Ch5 z5e gases

blachman

Borax

Karl Fischer Titration

Niloy Hassan

Handling Difficult Samples in Karl Fischer Analysis

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Effect of variation in temperature & pH levels on the activity of salivary am...

Nidhi Sharma

Biochemistry lab reporttt

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11 kf-theory jntu pharmacy

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Dc lab 5

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Biochemistry lab reporttt

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Lab 9 Chemical Reactions IIPre-lab Questions1. What is a limi.docx

smile790243

Lab 9: Chemical Reactions II Pre-lab Questions 1. What is a limiting reagent? 2. A student used 7.15 g of CaCl2 and 9.25 g of K2CO3 to make CaCO3. The actual yield was 6.15 g of CaCO3. Calculate the limiting reagent and the percent yield. Experiment: Synthesis of Garden Lime Procedure **Take photographs of your experiment set up and your results. Submit them with your laboratory report.** 1. Table 1 provides an example set of data for 1.0 g CaCl2. 2. For Trial 1, weigh into a 250 mL beaker the amount of calcium chloride (CaCl2) shown in Table 1. Record the exact mass you weigh out in the Trial 1 column of the Data section. 3. Measure 50.0 mL of distilled water into a 100 mL graduated cylinder. Pour the water into the 250 mL beaker with the calcium chloride. 4. Stir the solution with a stirring rod until all of the calcium chloride is dissolved. 5. Weigh out 2.5 g of potassium carbonate (K2CO3) in a 50 mL beaker. Record the exact mass in the Data section. 6. Measure 25.0 mL of distilled water into a 100 mL graduated cylinder. Add the water into the 50 mL beaker containing the potassium carbonate. 7. Stir the potassium carbonate in the distilled water with a stirring rod until it is all dissolved. 8. Pour the K2CO3 solution into the 250 mL beaker that has the CaCl2 solution. Rinse the beaker that contained the K2CO3 with a few mL of water and add this to the CaCl2 solution. Stir the mixture. 9. As soon as the reaction begins, record your observations in the Data section. Continue stirring until you see no more precipitate forming. 10. Set up the funnel in the Erlenmeyer flask as shown in Figure 2. HINT: Do NOT begin filtering yet! 11. Zero the scale and weigh a piece of filter paper and a watch glass. Record the masses of both items in the Data section. 12. Prepare a filtering funnel as shown in Figure 2: fold a piece of filter paper in half twice to make quarters, and open the paper to make a small cone (three quarters are open on one side and one quarter is on the opposite side). Place the paper cone into the funnel and hold it in place with your fingers. Pour a small amount of distilled water through the paper to secure it inside the funnel. 13. Filter the mixture by pouring it into the filter paper in the funnel. Use the stirring rod and distilled water in a wash bottle to transfer the entire solid into the filter paper. HINT: For best results, be sure to transfer all of the precipitate into the filter paper. Use a rubber policeman if it is available to help with the transfer. 14. Rinse the remaining solid in the filter paper twice with distilled water from a wash bottle to rinse off excess sodium chloride (NaCl). After all the liquid has filtered through, rinse the product with approximately 5 mL of ethanol to aid in its drying. Allow the ethanol to completely finish filtering through the paper. 15. Remove the filter paper carefully so as to not lose any product. Gently unfold the filter paper and lay it flat on the pre-weighed wat ...

phychem1phychem2Lab 9 Chemical Reactions IIPre-lab Qu.docx

mattjtoni51554

This document provides the procedure for a chemistry lab experiment involving chemical reactions. The experiment involves synthesizing calcium carbonate and determining the limiting reagent and percent yield. Students will carry out two trials of the reaction of calcium chloride and potassium carbonate solutions to produce calcium carbonate precipitate. They will calculate the theoretical and actual yields, identify the limiting reagent, and calculate the percent yield for each trial. The procedure provides detailed steps for setting up the reaction, filtering and drying the product, collecting data, and performing calculations to analyze the results.

Chemical Reactions 2

projecteciencies

This document outlines the purpose, procedure, and experiments for a chemistry lab activity on chemical reactions. The purpose is to observe different types of chemical reactions, identify reaction types, predict products, and write and balance chemical equations. The procedure involves setting up reactions in test tubes, recording observations, and cleaning up. Experiment 1 mixes zinc and copper nitrate, Experiment 2 mixes ammonium hydroxide and copper nitrate, and Experiment 6 dissolves iron chloride and sodium hydroxide in water.

Micro chemlab

Loren Copernicus

This document describes a laboratory experiment to determine the concentration of hydrogen peroxide in a commercial antiseptic solution through redox titration. Potassium permanganate is used as the titrant to oxidize hydrogen peroxide. By measuring the volume of permanganate needed to reach the endpoint of the reaction, the concentration of hydrogen peroxide can be calculated. The purpose is to verify if the 3% concentration listed on commercial products is accurate. The procedure involves titrating a sample of the hydrogen peroxide solution with a standard permanganate solution and recording the volumes used in multiple trials to calculate an average concentration.

Micro chem

Loren Copernicus

This document describes a procedure to determine the concentration of hydrogen peroxide in a commercial antiseptic solution through redox titration. Potassium permanganate is used as the titrant to oxidize hydrogen peroxide. By measuring the volume of permanganate needed to reach the endpoint of the reaction, the concentration of hydrogen peroxide can be calculated. The purpose is to verify if the 3% concentration listed on commercial products is accurate. The procedure involves titrating a sample of the product against a standard solution of permanganate while monitoring the color change, and using the reaction stoichiometry and volumes to calculate the concentration.

E q u i l i b r i u m D e t e r m i n a t i o n o f a n E

AlyciaGold776

E q u i l i b r i u m : D e t e r m i n a t i o n o f a n E q u i l i b r i u m C o n s t a n t P u r p o s e To determine the equilibrium constant of a reaction. L e a r n i n g O b j e c t i v e s Take a reaction to equilibrium by setting up and monitoring a reaction in a reflux apparatus. Measure the amount of acid at equilibrium by carrying out an acid-base titration. Apply the information from a balanced chemical equation and data obtained in the laboratory to determine the concentrations of reactants and products at equilibrium. Calculate the value of the equilibrium constant using data obtained in the laboratory. L a b o r a t o r y S k i l l s To set up and monitor a reflux apparatus. To carry out an acid-base titration. E q u i p m e n t Two 50-mL graduated cylinders Two 125-mL Erlenmeyer flasks 1-mL pipet 25-mL buret Equipment necessary to assemble the reflux apparatus shown in Figure 1. C h e m i c a l s Anhydrous ethanol (ethyl alcohol) Anhydrous acetic acid Concentrated sulfuric acid I n t r o d u c t i o n From the beginning of this course, we have generally assumed that chemical reactions go to completion, that is, the reaction proceeds in the forward direction until one of the reactants is completely used up. However, many reactions do not go to completion and are able to move both in the forward and reverse directions simultaneously. Such a reaction is called a reversible reaction. A double arrow in the chemical equation designates a reversible reaction, as shown in Reaction 1: aA + bB −−−⇀↽−−− cC + dD (Reaction 1) 1 D e t e r m i n a t i o n o f a n E q u i l i b r i u m C o n s t a n t A reversible reaction has two reaction rates: a forward reaction rate, where the reactants A and B are consumed andtheproductsCandDareproduced,andareversereactionrate,wheretheproductsCandDareconsumedand thereactantsAandBareproduced. Allreversiblereactionseventuallyreachapointatwhichtheforwardreaction rate equals the reverse reaction rate. This point is called equilibrium. At equilibrium, the concentration of reactants and products do not change with time. It is important to remember that even though the concentration of reactants and products do not change with time, the reaction has not stopped. Equilibrium is a dynamic state. The state will persist as long as the reaction conditions remain constant. A reaction at equilibrium follows the law of mass action which gives the relationship between concentrations of the reactants and products at equilibrium. According to the law of mass action, the relationship between concentrations of reactants and products at equilibrium for the above reaction is given in Equation 1: 𝐾eq = [C]𝑐[D]𝑑 [A]𝑎[B]𝑏 (Equation 1) Thisrelationshipiscalledtheequilibrium-constantexpression. Theconstant, 𝐾eq, isapositivenumberwhose value depends on the reaction and temperature. In today’s experiment, students will be determining the equilibrium constant for the reac

Water Testing Lab Background Information Chemists can .docx

celenarouzie

Water Testing Lab Background Information: Chemists can detect and identify ions in water solution in several different ways. In this lab you will use some chemical tests to check for the presence of certain ions in aqueous solution. Positively charged ions are called cations; negatively charged ions are called anions. The tests you will perform are confirming tests. If the test is positive, it confirms that the ion in question is present. In each confirming test you will look for a change in solution color, or the appearance of an insoluble material called a precipitate. A negative test (no color change or precipitate) doesn’t necessarily mean the ion in question is not present. The ion may simply be present in such a small amount that the color or precipitate cannot be seen. Purpose: § To use chemical tests to determine the presence of ions in three different water samples. Objectives: § To test for the presence of cations iron (III) Fe3+, calcium Ca2+, copper Cu+, as well as the anions chloride Cl-, phosphate PO43-, and sulfate SO42-. § To perform each of the following confirming tests on three different samples: 1. A reference solution (known to contain the ion of interest) 2. Tap water (which may or may not contain the ion) 3. A control (distilled water, known not to contain the ion) § Test for water hardness using ion-testing strips. § Complete a confirmative ion-testing using a complete ion-testing strip. Materials: § 10 test tubes § Test tube rack § 10 mL graduated cylinder § Test reagent solutions in dropper bottles o Potassium thiocyanate (KSCN) o Potassium oxalate (K2C2O4) o Acetic acid (HC2H3O2) o Silver nitrate (AgNO3) o Barium Chloride (BaCl2) § Reference ion solutions o Iron (III) Nitrate - Fe(NO3)3 o Calcium Chloride – CaCl2 o Iron (II) Sulfate – FeSO4 Procedures: PART ONE 1. Safety goggles should be worn at ALL times during this lab exercise. If you spill any of the reagents on your hands, wash them immediately. 2. Clean five test tubes with water and dry all glassware before starting the experiment. 3. In this lab, you are testing water samples for the presence of four different ions: Ca2+, Fe3+, Cl-, and SO42-. For EACH of the test procedures you will test a reference solution (known to contain the ion), a control (distilled water-known not to contain the ion), and your water samples brought from home. Follow the diagram below and be sure to keep track of your water samples: 4. Measure 1 pipette full (about 2 mL) of reference solution, control, and the three water samples into five clean test tubes. Label the three test tubes Reference (R), Control (C), and Water Sample #1, 2, & 3. 5. Follow the table below to test for each ion: 6. As you perform each test, record your observations in the data table below. 7. When you have completed an ion test, wash your test tubes with water and dry them thoroughly before moving on to the next ion test. P.

Liver prac

1. The document describes an experiment investigating factors that influence the rate of a chemical reaction catalyzed by the enzyme catalase. Liver tissue and hydrogen peroxide were used to test the effects of grinding, temperature, and controls. 2. Grinding the liver tissue increased the rate of reaction compared to using intact tissue, likely by increasing the surface area exposed to hydrogen peroxide. 3. Exposing liver tissue to heat reduced catalase activity, probably by denaturing the enzyme's structure.

Liver prac

This document describes an experiment investigating factors that influence the rate of a chemical reaction catalyzed by the enzyme catalase. Students tested the effect of grinding liver tissue, as well as heating liver tissue to boiling, on the rate of hydrogen peroxide breakdown. Grinding liver tissue increased the rate of reaction compared to using intact tissue. Boiling liver tissue decreased its catalytic activity, likely by denaturing the catalase enzyme.

Enzyme activity

1. The experiment investigated factors that influence the rate of a chemical reaction catalyzed by the enzyme catalase. Liver tissue and hydrogen peroxide were used to test the effects of grinding, temperature, and controls. 2. Grinding the liver tissue increased the rate of reaction compared to whole tissue, likely by increasing the surface area exposed to hydrogen peroxide. 3. Boiling the liver tissue reduced its catalytic activity, probably by denaturing the catalase enzyme.

Liver prac

This document describes an experiment investigating factors that influence the rate of a chemical reaction catalyzed by the enzyme catalase. Students tested the effect of grinding liver tissue, as well as heating liver tissue to boiling, on the rate of breakdown of hydrogen peroxide into water and oxygen catalyzed by catalase. Grinding liver tissue increased the rate of the reaction compared to using intact liver tissue. Boiling liver tissue decreased the rate of the reaction, likely by denaturing the catalase enzyme.

AcidBase ChemistryPortland Community College StaffVersio.docx

bobbywlane695641

Acid/Base Chemistry Portland Community College Staff* Version 42-0137-00-01 Lab Report Assistant This document is not meant to be a substitute for a formal laboratory report. The Lab Report Assistant is simply a summary of the experiment’s questions, diagrams if needed, and data tables that should be addressed in a formal lab report. The intent is to facilitate students’ writing of lab reports by providing this information in an editable file which can be sent to an instructor. Observations In columns 3 and 4, record the color and intensity seen. In columns 5 and 6, determine if the substance is an acid or a base, and if the substance is ionic. For the last column, determine which chemical species is acting as an acid or base. Data Table 1: Acids and Bases Acting in Water Well Substance 1drop BTB Plus 1 drop of substance Acid or base (Q1) Ionic? Y/N (Q2) Species acting as acid or base (Q3) 1 NaHCO3 2 CH3COOH 3 HCL 4 Na2CO3 5 H2SO4 6 CH3COONa 7 NaOH 8 HNO3 9 NaHSO4 10 NH3 11 H3PO4 12 NaH2PO4 13 Na2HPO4 14 Na3PO4 15 NaHSO3 Data Table 2: Following Acid/Base neutralization reactions Well # 1 Drop of Each Observation +2 Drops Acid Observation +2 Drops Base Observation 1 BPB + NaOH HCl NaOH 2 BPB + NaOH H2SO4 NaOH 3 BPB + NaOH CH3COOH NaOH 4 BPB + NaOH H3PO4 NaOH 5 BPB + Ca(OH)2 HCl Ca(OH)2 6 BPB + Ca(OH)2 H2SO4 Ca(OH)2 7 BPB + Ca(OH)2 CH3COOH Ca(OH)2 8 BPB + Ca(OH)2 H3PO4 Ca(OH)2 9 BPB + NH3 HCl NH3 10 BPB + NH3 H2SO4 NH3 11 BPB + NH3 CH3COOH NH3 12 BPB + NH3 H3PO4 NH3 Please note here if any of the other starting materials is other than a clear, colorless solution. Data Table 3: Investigating Odor as a Means of Indicating Neutralization. Substance(s) Odor 2 Drops of HCl in Well #1 1 Drop of Ammonia on Swab Swab with Ammonia & HCl Data Table 4: Investigating Evaporation as a Means of Indicating a Neutralization Reaction. Reaction Mixture Observation (When Wet) Observation (When Dry) HCl + NaOH CH3COOH + NH3 HNO3 + NaOH PART 5: Mini-Experiments 1. Use BTB to classify four household products as acidic or basic. Possible substances to test include home cleaning products, glass cleaner, liquid detergent, bleach, soft drinks, liquid from food items, etc. Remember to: a. Hypothesis (What you think will happen and why) or purpose: b. Method used to test your hypothesis: c. Data and Observations Put your data and observations in the space below. You can include pictures that you “draw.” d. Conclusions 2. Find one common, highly colored substance that can be used as an acid-base indicator. Possible substances include fruit/vegetable juice or products, inks, food coloring, flower petals, etc. If using fresh fruit, veggies, or flo.

Bio Catalyze Lab

tangkwa22

The document describes a student's lab experiment investigating the effect of temperature on the activity of the enzyme catalase. Catalase breaks down hydrogen peroxide and was tested at four temperatures (3°C, 25°C, 45°C, and 60°C) using chicken liver. The student measured gas pressure over time for each trial and found that the enzyme worked best at 45°C based on the peak average pressure. Limitations included a lack of time, materials, and temperatures tested to draw stronger conclusions.

Le chatelier equilibrium

1) The document discusses Le Châtelier's principle and how chemical equilibriums respond to changes in concentration, temperature, volume or pressure by shifting to counteract the imposed change. 2) It then describes several experiments involving acid-base indicators, the solubility product constant (Ksp) for lead chloride, complex ion equilibriums involving cobalt chloride, and dissolving insoluble salts like zinc hydroxide through the addition of reagents. 3) The experiments are meant to demonstrate Le Châtelier's principle in chemical systems at equilibrium and how the addition of various reagents can shift the equilibrium by changing concentrations or forming new complexes.

Haloalkanes haloarenes bounce back.pdf

ZakiAli40

The document discusses haloalkanes and haloarenes. It provides information on: - Physical properties of haloalkanes such as solubility, melting/boiling points, and polarity. - Nucleophilic substitution reactions (SN1 and SN2) of haloalkanes including factors affecting the reactions. - Elimination reactions (E1, E2, E1cb) of haloalkanes including factors affecting the reactions. - Methods of preparation of haloalkanes such as halogenation of alkanes, hydrohalogenation of alkenes, and from alcohols.

LabQuest 18 Chemistry with Vernier 18 - 1 Additi.docx

MARRY7

LabQuest 18 Chemistry with Vernier 18 - 1 Additivity of Heats of Reaction: Hess’s Law In this experiment, you will use a Styrofoam-cup calorimeter to measure the heat released by three reactions. One of the reactions is the same as the combination of the other two reactions. Therefore, according to Hess’s law, the heat of reaction of the one reaction should be equal to the sum of the heats of reaction for the other two. This concept is sometimes referred to as the additivity of heats of reaction. The primary objective of this experiment is to confirm this law. The reactions we will use in this experiment are: (1) Solid sodium hydroxide dissolves in water to form an aqueous solution of ions. NaOH(s) Na+(aq) + OH–(aq) H1 = ? (2) Solid sodium hydroxide reacts with aqueous hydrochloric acid to form water and an aqueous solution of sodium chloride. NaOH(s) + H+(aq) ) + Cl–(aq) H2O(l) + Na+(aq) + Cl–(aq) H2 = ? (3) Solution s of aqueous sodium hydroxide and hydrochloric acid react to form water and aqueous sodium chloride. Na+(aq) + OH–(aq) + H+(aq) ) + Cl–(aq) H2O(l) + Na+(aq) + Cl–(aq) H3 = ? In the space below, combine two of the above equations algebraically to obtain the third equation. Indicate the number of each reaction on the shorter lines. ______ __________________________________________________________________ ______ __________________________________________________________________ ______ __________________________________________________________________ You will use a Styrofoam cup in a beaker as a calorimeter, as shown in Figure 1. For purposes of this experiment, you may assume that the heat loss to the calorimeter and the surrounding air is negligible. Even if heat is lost to either of these, it is a fairly constant factor in each part of the experiment, and has little effect on the final results. You will make three grand assumptions in this experiment: 1. The specific heat of solution is equivalent to the specific heat of water. 2. The density of solution is equivalent to the density of water. 3. All solutions are identical in temperature before mixing. OBJECTIVES In this experiment, you will Combine equations for two reactions to obtain the equation for a third reaction. Use a calorimeter to measure the temperature change in each of three reactions. Calculate the heat of reaction, H, for the three reactions. Use the results to confirm Hess’s law. LabQuest 18 18 - 2 Chemistry with Vernier MATERIALS LabQuest 4.00 g of solid NaOH LabQuest App ring stand Temperature Probe utility clamp 50 mL of 1.0 M NaOH stirring rod 50 mL of 1.0 M HCl Styrofoam cup 100 mL of 0.50 M HCl 250 mL beaker 100 mL of water PROCEDURE Reaction 1 1. Obtain and wear goggles. 2. Connect the Temperature Probe to LabQuest and choose New from the File menu. If you have an older sensor that does not auto-ID, manually ...

CHE107 - class 07 - Pre lab lecture

Sadie Novak

This document provides instructions for Lab 7 on water quality testing. It discusses titrating calcium, magnesium, and total hardness in tap water samples using EDTA. Students are instructed on the proper procedure, calculations, and safety precautions for the lab. Key points covered include the 1:1 mole ratio of Ca2+/Mg2+ to EDTA, identifying the color change endpoints, and calculating concentrations and water hardness in terms of ppm CaCO3. Students are also directed to review concepts from previous labs on units, significant figures, percent error, and solution preparation.

Bradley Open Notebook Science ACSfall2012

Jean-Claude Bradley

Jean-Claude Bradley presents at the American Chemical Society meeting on August 20, 2012. Examples are first presented to demonstrate how access to Open Notebooks can provide critical information not usually shared in the traditional publication process. The use of Google App Scripts to look up chemical properties allows for the use of Google Spreadsheets as a self-contained dashboard to plan and analyze chemical reactions. The concept of the Open Chemical Property Matrix (OCPM) is introduced and a smartphone app to suggest recrystallization solvents is then presented.

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