chapter 3

Question 1

avg. mass formula

Answer 1

(%)(mass) + (%)(mass) + ….

Question 2

avogadros number

Answer 2

The number equals the number of carbon atoms in exactly 12g of pure carbon 12

Question 3

1 mole of something consists of…

Answer 3

6.022 x 10^23 units of that substance

Question 4

1 mole of something gives you…

Answer 4

the same number of molecules as 1 mole of a different substance

Question 5

molar mass

Answer 5

the number of grams in one mole of a substance

Question 6

mass percent formula

Answer 6

[(# of an element x molar mass) / (molar mass of a compound) ] x 100

Question 7

hydrate

Answer 7

Compounds that have specific numbers of water molecules attached to them

Question 8

how are hydrates written?

Answer 8

chemical formula than “x” the # of water molecules

Question 9

empirical formula

Answer 9

simplest whole ratio of elements

Question 10

molecular formula

Answer 10

exact number of elements in a compound

Question 11

rules of balancing a chemical equation

Answer 11

1. determine which chemical reaction is occurring. what are the reagents, products, and physical states?
2. write unbalanced equation
3. balance
4. do not change subscripts

Question 12

calculating masses of reactants and products

Answer 12

1. balance
2. convert known masses to moles
3. use the balanced equation to set up mole ratios
4. calculate the unknown mole quantities then convert back to grams

Question 13

percent yield

Answer 13

[(actual yield) / (theoretical yield)] x 100