Worksheet #2

Ar

100

Relative atomic mass (Ar) of Kr is

84

200

Relative atomic mass (Ar) of Cu is

63.5

300

Given the following table shown abundance percentage of silicon isotopes:

• Si-28 27.977 amu; 92.23%
• Si-29 28.976 amu; 4.67%
• Si-30 29.794 amu; 3.1%

Relative atomic mass (Ar) of Si is …

28.0799 amu

M

100

What is the molar mass of S₈ ?

256 g/mol

200

What is the molar mass of Fe₂O₃ ?

160 g/mol

300

What is the molar mass of NH₄NO₃?

80 g/mol

m

100

Mass of 5.0 mol MgCl₂ is

475 g

200

Mass of 5.0 mol NaHCO₃ is

84 g

300

Mass of 9.03 x 10²⁴ molecules of CO(NH₂)₂ is

903 g

n

100

The number of moles in 24.5 g of sulfuric acid, H₂SO₄ is

0.25 mol

200

The number of moles in 12.0 g of NaOH is

0.3 mol

300

Moles of 2.07 g of ethanol, C2H5OH is

0.045 mol