Chapter 3 - Calculations with Chemical Formulas and Equations (Stoichiometry)

Question 1

The number of AMU is determined by?

Answer 1

the mass in grams of 1 mole of atoms

Question 1

How many grams of Carbon are in 12 AMU of Carbon (12C)

Answer 1

12 grams C

Question 2

1 mole of 12C has a mass of how many grams?

Answer 2

12 grams

Question 3

What is Avogadro’s number (Na)?

Answer 3

6.022 x 10^23

Question 4

Formula for molar mass

Answer 4

(mass in grams)/(1 mole of atoms) g/mol

Question 5

Find the molecular weight of H2O given H: 1.01 and O: 16.00

Answer 5

(2 x 1.01) + 16.00 = 18.02 g/mol

Question 6

Find the molecular weight of CHCl3 given C: 12.011, H: 1.01, Cl: 35.45

Answer 6

12.011 + 1.01+ (3 x 35.45) = 119.4 g/mol

Question 7

What percent of water is made up of H given that 11.19 g of H is in 100g of H2O?

Answer 7

11.19/100 X 100 = 11.19%

Question 8

What is the mass percent of each element in dinitrogen oxide (N2O)?
Given: N: 14.01 and O: 16.00

Answer 8

2 moles of N and 1 mole of O
N -> 2 x 14.01 = 28.02
O -> 16.00
28.02 + 16.00 = 44.02 g/mol
N: 28.02/44.02 x 100 = 63.65 % N
O: 16.00/44.02 x 100 = 36.35% O