Stoichiometry

a quantitative study of chemical reactions

Ex: How many grams of potassium phosphate will react with

100g of magnesium nitrate? How much precipitate will form?

First 3 things to learn p.81

Molar mass mole avogadro’s numberFormula massMolecular massAtomic massFormula weightMolecular weightAtomic weightAtomic mass units

Molar mass is the mass in grams of one mole of the compound

Ex) carbon monoxide molar mass = 28.01 grams CO….carbon=12.01amu + oxygen = 16.00 amu ……..28.01 grams

sodium chloride molar mass = 58.45 grams NaCl…..sodium= 22.99 amu + chlorine= 35.45amu…….58.44 grams

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Mole or molMole ==== dozen cars

eggsvolcanos

Mole = the amount of substance that contains the same number of particles as 12.01 grams of carbon 12.

A chemist may want 1mol of Carbon = 12.01grams1mol of Iron = 55.85grams1mol of Calcium =

40.08grams

1mol of H20 = 18.016 grams

1mol of FeSO4=151.92 grams

***units are just as important as numbers***** units tell you to multiply or divide **

1. How many moles are in 11 grams of Sodium?

2. How many grams in 2.7mol of Phosphorus?

3. How many moles are in 23grams of Krypton?

4. How many grams are in 86.93mol of Calcium?

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5. How many moles are in 5.6 grams of Magnesium?

6. How many grams are in 242 moles of arsenic?

7. How many moles are in 2.7grams of Sodium Hydroxide?

8. How many moles are 52.5 grams of Copper II Sulfate?

9. How many grams are in 75 moles of water?

10.How many moles are in 1.7 x 105 grams of methane?

11. How many grams are in 4.3 x 10-6 moles of Calcium phosphate?

12. How many grams are in 18.37 x 10-2 moles of silicon dioxide?

13. How many moles in 2.3 x 103 grams of potassium sulfide

14. How many grams in 15 moles of hydrochloric acid?

15. How many grams in 132 x 105 moles of Manganese?

16. How many grams in 232 x 103 moles of aluminum hydroxide?

1x 102 = hundred

1x 103 = thousand

1x 106 = 1 million

1x 109 = 1 billion

1x 1012 = 1 trillion

l million = spend $1,000.00/day

starting today ,

1 billion = spend $1000.00/day

start day, 600BC---

1 trillion = spend $1000.00/second……$1.444 million per day

need ___________ years to spend it

Avagadro’s number = 6.022 x 1023

One mole of anything has avagadro’s number in it. atoms in it

Avagadro’s # 6.022 x 1023 molecules in it

One mole of mm’s will cover the United States…. How deep?

1 mol of Cu has 6.022 x 1023 atoms1 mol of Ag has 6.022 x 1023 atoms 1 mol of H20 has 6.022 x 1023 molecules1 mol of CuSO4 has 6.022 x 1023 molecules

***word units are as important as the numbers***“word units tell if multiplying or dividing”

“because every experiment is different…...there is no set pattern or formula”

“the word unit to eliminate goes opposite”

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l. How many molecules in 28grams of Sodium Sulfate?

2. How many moles in 28grams of Sodium Sulfate?

3 How many grams in 7.5 x 1028 molecules of SilverNitrate

4. How many moles in 7.5 x 1028 molecules of SilverNitrate?

5. How many moles in 120x1042 molecules of Sodium Chloride?

6. How many molecules in 25g of Sodium Chloride?

7. How many molecules in 122g of Copper II Nitrate?

8. How many grams in 9.4 x 1025 molecules of hydrogen gas?

9. How many molecules in 230 moles of Cobalt II Chloride?

10. How many moles are in 9.4 x 1025 molecules of Sulfuric Acid?

11. How many grams are in 9.4 x 1025 molecules of Sulfuric Acid?

12. How many molecules are in 255 grams of Ammonium Hydroxide?

14. How many molecules of Aspirin are in one pill? One pill is .2g. Aspirin(C9H8O4)

15. How many moles of Aspirin in 2 pills?

16. How many molecules of Cocaine would a drug addict pump in his blood stream if the person used one gram? Cocaine ( C17H21NO4)

AP-problem; p.93Isopentyl acetate is the compound responsible for the scent of

bananas. Interestingly bees release about 1ug(1 X 10-6g) of this compound when they sting. The resulting scent attracts other bees to join the attack.

How many molecules of isopentyl acetate( C7H14O2) are released in a typical bee sting?

How many atoms of Carbon are present?

Note:

1 mole of CH4 contains

1mole of carbon and 4moles of hydrogen