First Term ReviewInstructions: Answer the following questions. Type your answers except for themathematical problems (thos...
6. What’s the difference between intensive and extensive properties? Exemplifyyour answer.7. Do chemical reactions affect ...
14. Using the following data, calculate the average atomic mass of an unknownelement and determine what element it is:Mass...
19. Identify a substance that when poured into a graduated cylinder the volume is35.1 mL and has a mass of 30.5 g.Substanc...
23. What element do I have in a sample with a mass of 3 grams and about    2.287x1022 atoms.1. In order to identify the el...
Upcoming SlideShare
Loading in …5
×

First term review answers

832 views
720 views

Published on

Revised Version

Published in: Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
832
On SlideShare
0
From Embeds
0
Number of Embeds
3
Actions
Shares
0
Downloads
4
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

First term review answers

  1. 1. First Term ReviewInstructions: Answer the following questions. Type your answers except for themathematical problems (those should be done by hand).Some of the questions will be counted toward extra points for other assignmentsbut you should answer all questions.Review is due on Friday September 2nd, 2011.1. Define the following words if pertainable give examples:ChemistryMatterSubstanceSustainabilityMassWeightModelAtomic levelEnergyElementsCompoundsHomogenous mixturesHeterogeneous mixtureElectronProtonNeutronSubatomic particlesNuclide symbol and its parts2. What are CFC’s? How do they affect our environment?3. Give three examples of SI units and what they measure.4. What are prefixes used for?5. Describe three phase changes and where they can occur.
  2. 2. 6. What’s the difference between intensive and extensive properties? Exemplifyyour answer.7. Do chemical reactions affect our environment? How? Give specific examples.8. What law does the following scenario describe? One gram of Sodium Chloride always contains 0.3934 grams of Sodiumand 0.6066 grams of Chlorine.9. Describe the following as a cation, anion, or polyatomic ion.Ni2+Te2-NH4+N3-Rb+HPO42-10. How are isotopes differentiated?11. Make a time line of the evolution of the atomic theory (write scientist namesand their experiments).12. What information about an element can you find in the periodic table?13. Write the formula for the following ionic compounds:Fe2+ PO43- Iron (II) Phosphate Fe3(PO4)2Ti4+ O2- Titanium (IV) Oxide Ti2O4 2+ -Mg Br Magnesium Bromide MgBr2
  3. 3. 14. Using the following data, calculate the average atomic mass of an unknownelement and determine what element it is:Mass number Isotopic Mass (amu) Fractional Abundance50 49.9461 0.043552 51.9405 0.837953 52.9407 0.095054 53.9389 0.0236Average Atomic Mass = (49.9461)(0.0435) + (51.9405)(0.8379) + (52.9407)(0.0950) + (53.9389)(0.0236)Average Atomic Mass = 51.9956 amuChromium15. Two samples of different compounds of nitrogen and oxygen have thefollowing composition. What are the two compounds? What law can you use tosolve this problem? Amount N Amount O Mass ratio (O g/N g)Comp A 1.206 g 2.755 g 2.755/1.206 = 2.2844Comp B 1.651 g 4.714 g 4.714/1.651 = 2.8551Whole Small Number Ratio = 2.2844/2.8551 = 1.2499 = 1.25 = 5/4Compound A – NO4Compound B – NO516. What is the mass percent of carbon in CH2O?Mass percent = mass of element / total mass * 100Mass percent = 12.011g/mol / (12.011 + 2*1.01 + 15.999) g/mol * 100Mass percent = 39.997 %17. The world’s oceans contain approximately 1.35 x 109 km3. What is thevolume in liters?1.35 x 109 km3 (1000 m)3 (10 dm)3 1L = 1.35 x1021 L (1 km)3 (1 m)3 1 dm318. A sample of nitrogen gas in a glass bulb weighs 243 mg. What is this mass inSI base units of mass?243 mg 1g 1 kg = 2.43 x10-8 kg 1000 mg 1000 g
  4. 4. 19. Identify a substance that when poured into a graduated cylinder the volume is35.1 mL and has a mass of 30.5 g.Substance Density (g/mL)n- butyl alcohol 0.810ethylene glycol 1.114isopropyl alcohol 0.785toluene 0.866 1. Find the density of the substance you have: D = 30.5 g / 35.1 mL = 0.869g/mL 2. Compare it to the given chart: Toluene20. Write the following in terms of the SI base unit (write them in scientificnotation)a. 1.07 ps b. 5.8 micrometerc. 19.6 ms d. 15.3 msa) Base unit for time: seconds1.07 ps 1s = 1.07x10-12 s 1x1012 psb) Base unit for length: meter5.8 micrometers 1 meter = 5.8x10-6 meters 1x106 micrometersc) Base unit for time: seconds19.6 ms 1s = 1.96x10-4 s 1000 msd) Base unit for time: seconds15.3 ms 1s = 1.53x104- s 1000 ms21. Tungsten metal, which is used in light bulb filaments, has the highest meltingpoint of any metal (3410oC). What is the melting point in degrees Fahrenheit?F = 1.8C – 32 à F = 1.8(3410) + 32 = 6170 F22. How many atoms of Pd are in 3 grams of Palladium? (Hint: use averageatomic mass in amu or g/mol and Avogadro’s number).1. Find the average atomic mass of Palladium: 106.42 g/mol3g mol 6.023x1023atoms= 1.698x1022 atoms 106.42 g mol
  5. 5. 23. What element do I have in a sample with a mass of 3 grams and about 2.287x1022 atoms.1. In order to identify the element you need to find its average atomic mass.3g 6.023x1023 atoms = 79.007 g/mol2.287x1022 atoms mol24. What do Pauli’s exclusion principle and Hund’s rule state?25. Give the electric configuration of the following elements.CaIMgNAl

×