Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. If you continue browsing the site, you agree to the use of cookies on this website. See our User Agreement and Privacy Policy.

Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. If you continue browsing the site, you agree to the use of cookies on this website. See our Privacy Policy and User Agreement for details.

Like this presentation? Why not share!

2,666 views

2,407 views

2,407 views

Published on

No Downloads

Total views

2,666

On SlideShare

0

From Embeds

0

Number of Embeds

1

Shares

0

Downloads

214

Comments

0

Likes

4

No embeds

No notes for slide

- 1. Chemistry - Moles A Demonstration to describe the concept of moles more briefly.
- 2. Part 1: Chemical Quantities
- 3. Introduction ● How did you determine the number of M&Ms in the bag without actually counting?
- 4. Atoms ● Can you determine the number of atoms of an element even though you can not actually count them? ● Yes… IF there is a conversion factor that allows you to convert between mass and number of atoms.
- 5. Moles ● The SI base unit that measures amount of substance ● Avogadro’s Number: 6.02 x 1023 atoms
- 6. Moles and Atomic Mass ● The atomic mass of an element in grams contains one mole of atoms (Avogadro’s number of atoms) ● Example: There are 6.02 x 1023 (or 1.0 moles) of atoms in 12.011 g of carbon
- 7. Moles as Conversion Factors ● Use moles/grams (or grams/moles) as a conversion factor ● Ex: 16.0 g oxygen ----------------------------- 1 mole oxygen
- 8. Example 1 ● How many moles of helium atoms are in 6.8 grams?
- 9. Example 2 ● How many grams is equal to 1.51 moles of iron?
- 10. Examples 3, 4, and 5 ● 17.6 grams of chlorine is equal to how many moles? ● How many moles of nickel do you have if you have 65.1 g? ● React 1.9 moles of sodium with chlorine gas to get sodium chloride. How many grams of sodium do you need?
- 11. Calculating Molar Mass ● Atomic Mass of an element = “molar mass” ● Molar mass of a compound must be calculated
- 12. Calculating Molar Mass ● How many oxygens are in a DOZEN water molecules? ● How many hydrogens?
- 13. Calculating Molar Mass ● One mole of WATER MOLECULES (H2 O) is one mole of oxygen atoms and two moles of hydrogen atoms ● Calculate the mass of one mole of water molecules
- 14. Calculate the molar mass of… ● Boron Trifluoride ● Sodium Iodide ● Sodium Bicarbonate (NaHCO3 ) ● Glucose (C6 H12 O6 ) ● Copper (III) Sulfate
- 15. REMEMBER! ● Molar mass is the mass of one mole of an element/compound. ● Molar mass has units of grams/mole. ● Molar mass can be used as a conversion factor to find grams or find moles.
- 16. What you should know so far: ●Explain the concept of a “mole” and give a definition ●Explain how one mole of an element is related to atomic mass ●Find the molar mass of an element (using correct units) ●Determine the number of grams/moles of a given element using molar mass ●Calculate the molar mass of a compound ●Determine the number of grams/moles of a given compound using molar mass
- 17. Making A Solution ● You want to make a solution by dissolving 4.00 moles of potassium nitrate in water. How many grams of the compound will you need?
- 18. Example! ● Calculate the number of moles in a 13.8-g sample of butane lighter fluid. The formula for butane is C4 H10 .
- 19. Find the mass of: ●0.702 mol Be. ●2.40 mol N2 . ●0.160 mol H2 O2 . ●5.08 mol NaNO3 . Find the number of moles. ●187 g Al ●0.264 g Li2 HPO4 ●333 g SnF2
- 20. ● How many grams are in 5.66 mol of CaCO3 ?
- 21. ● How many moles are in 508 grams of ethanol, CH3 CH2 OH?
- 22. Part 2: Moles of a Gas
- 23. Gases ● Solids/liquids are packed tightly together and more space is needed if atoms/molecules are larger ● Atoms/molecules in gases are far apart, so larger atoms/molecules do not need more space
- 24. Mole-Volume Relationship ● Avogadro’s Hypothesis – equal volumes of gases contain equal numbers of particles ● 1 mole of any gas takes up the same volume as long as…
- 25. STP ● …as long as the gases are at the same pressures and temperatures ● STP, or “standard temperature and pressure” means 0o C and 1 atmosphere, which is air pressure at sea level
- 26. Calculating Moles of a Gas ● At STP, a mole of any gas takes up 22.4 liters. ● Use 22.4 L /mol as a conversion factor!
- 27. Example 1 ● How many liters will a 0.19-mole sample of oxygen gas take up?
- 28. Example 2 ● A blimp has a volume of 95 kL (95,000 L). If it is filled with helium at STP, how many moles of the gas are contained within the blimp?
- 29. Examples 3 and 4 ● Find the number of moles in a sample of chlorine gas stored in a 14.2-liter tank at STP. ● What is the volume of 0.18 moles of xenon at STP?
- 30. During Last Week’s Episode… ● Look up molar mass of elements / calculate molar mass of compounds ● Convert moles-grams using molar mass as the conversion factor (elements and compounds) ● Convert moles-liters of a gas using molar volume (22.4 L/mol)
- 31. MOLES Mass (g) Volume (L) # Atoms Conversion Factor: molar mass Conversion Factor: molar volume (22.4 L / 1 mol) Conversion Factor: Avogadro’s number 6.02 x 1023 atoms/mol
- 32. Challenge Problem ● Calculate the mass of 16.4 L of chlorine gas at STP.
- 33. Part 3: Molarity
- 34. Molarity Molarity is a measure of how concentrated a solution is Amount of solute per volume of solution High concentration / high molarity
- 35. Molarity Measured in units of moles/liter mol/L = “M” A 2.5 M solution has 2.5 moles of salt in one liter of water
- 36. Molarity Problems To make one liter of a 2.5 molar solution of sodium chloride, how many grams of sodium chloride do you need?
- 37. Molarity Problems SET MOLARITY PROBLEMS UP AS A PROPORTION! ●How many moles of silver nitrate (AgNO3 ) are in 0.4 L of a 6.0 M solution? ●How many grams of silver nitrate is that?
- 38. Molarity Problem #3 How many grams of lead(IV) chloride must be dissolved in 50 mL of water to make a 0.1 M solution? Remember: 0.1 M = 0.1 mol/L
- 39. Molarity Problem #4 ●If you dissolve 56 g of sugar (sucrose, C12 H22 O11 ) into a liter of water, what is the molarity of the solution you created?
- 40. Part 3: Percent Composition Section 10.3, page 305
- 41. ● Methane, CH4 , is made of solely hydrogen and carbon. What percent of the compound is hydrogen? What percent is carbon?
- 42. Percent Composition ● Remember that some atoms are larger, by mass, than others ● Mass of each atom must be taken into account when calculating percent composition
- 43. Percent Composition ● Percent composition = % (by mass) of each atom in a compound mass of element % composition = --------------------------- x 100% mass of compound
- 44. Example 1 ● 15.1 grams of oxygen combine with 1.9 g of hydrogen to make water. Find the percent composition of each element.
- 45. Example 2 ● A sample of glucose is synthesized from 58.00 g carbon, 9.73 g hydrogen, and 77.27 g oxygen. Find the percent composition for each element.
- 46. Percent Composition and Chemical Formulas ● Allows you to find the % composition of an element in a compound without knowing the mass of that element molar mass of element % composition = --------------------------------------- x 100% molar mass of compound
- 47. Example 1 ● What percentage of a sample of table salt, sodium chloride, is sodium?
- 48. Example 2 ● Determine the percent composition of iron (III) oxide.
- 49. Example 3 ● Hypochlorous acid is one of the active sanitizers in pool-cleaning products. Its formula is HClO. What percent of the compound is oxygen?
- 50. Using Percent Composition to Calculate Mass ● To calculate mass of one element in a specific mass of a compound, multiply the mass of the compound by the percent composition of that element.
- 51. Using Percent Composition to Calculate Mass ● Example: ● Carbon is 27.3% of CO2 . Of 45.1 g of CO2 , what mass is carbon? 27.3% x 45.1 g = 12.3 g
- 52. Example 1 ● Find the number of grams of sodium in 10.1 g of sodium sulfate. ● HINT! First write the formula for sodium sulfate, then find the % sodium.
- 53. Thank You A Presentation by Irfad Imtiaz
- 54. Stay Tuned Facebook.com/IrfadImtiaz Twitter.com/IrfadImtiaz Slideshare.net/IrfadImtiaz http://www.irfadimtiaz.com

No public clipboards found for this slide

×
### Save the most important slides with Clipping

Clipping is a handy way to collect and organize the most important slides from a presentation. You can keep your great finds in clipboards organized around topics.

Be the first to comment