Unit 4 - The Mole

Question 1

What is a mole?

Answer 1

chemistries way of couning things and is based on 12g of pure carbon-12

Question 2

3 areas the mole counts

Answer 2

mass, volume, particles (atoms, molecules, formula units)

Question 3

how big is the mole?

Answer 3

1 mol=molar mass

Question 4

what is avogadros number

Answer 4

6.02 * 10^23

Question 5

what is dimensional analysis?

Answer 5

conversion factors, equalities, and factoring or using the idea to cancel units of measurements

Question 6

what is molar mass

Answer 6

1. the mass of one mole of an element or compound
2. the atomic mass amu expressed in grams

Question 7

what is percent composition

Answer 7

the percent that each atom contributes to the mass of a compound

Question 8

the calculation of percent composition is…

Answer 8

the part you are looking for divided by the whole thing times 100%

Question 9

empirical formula is…

Answer 9

the formula for a compound with the simplest whole number ratio for the compound

Question 10

how to get empirical formula

Answer 10

assume a 100g sample, convert % to mass and divide the mass by molar mass. then find a relationship between the calculated number of moles in a ratio

30.5 % N = 30.5g N
69.5 % O = 69.5g O

30.5g/14.01 = 2.17 mol N
69.5g/16.00 = 4.34 mol O

simplify ratio 2.17 : 4.34 to 1 : 2