Unit 6: Math of Chemical Formulas Honors

What is the molar mass of PbSO₄?

• 303.27 g/mol

• 255.27 g/mol

• 163.87 g/mol

• 372.27 g/mol

How many formula units are in 2.5 moles of NaCl?

• 1.5 x10²⁴ formula units

• 1.5 formula units

• 4.2 formula units

• 4.2 x10^-24 molecules

How many molecules are there in 31.8 moles of water?

• 5.28 x 10^-23 molecules
• 1.91 x 10²⁵ molecules
• 5.28x 10-²⁵
• 1.91 x 10²²

Determine the mass of 4.20 moles of C₆H₁₂

• 353 g

• 0.0499 g

• 337 g

• 2.53 x 10²⁴ g

Which of the following dimensional analysis setups will correctly convert 27.76 g of Li to atoms of Li?

• A

• B

• C

• D

What is the mass of 1.2 x 10²⁴ atoms of C?

• 2.0 grams

• 24 grams

• 0.17 grams

• 1.4 x 10²⁵ grams

Calculate the number of atoms in 0.0340 g Zn.

• 5.20 x 10^-4 atoms Zn

• 3.13 x 10²³ atoms Zn

• 3.13 x 10²⁰ atoms Zn

• 2.05 x 10²² atoms Zn

How many grams are in 1.2 moles of neon?

• 0.059 grams

• 7.2 x 10²³ grams

• 2.0 x 10^-24 grams

• 24 grams

What is the percent by mass of fluorine in CaF_{2 ,} which has a molar mass of 78 g/mol)?

• 24%

• 49%

• 51%

• 65%

What is the percent composition of benzene, C₆H₆?

• C = 50.%

  H = 50.%

• C = 85.7 %

  H = 14.3%

• C = 92.2%

  H = 7.8%

• C = 71.9%

  H = 28.1%