Review Mole Conversions

What percent of Zn₃(PO₄)₂ is zinc?

• 33.15%

• 16.04%

• 50.80%

• 19.68%

Find the percent composition of CaCl₂?

• Ca: 36.11%; Cl: 63.88%

• Ca: 53.12%; Cl: 100%

• Ca: 36.11%; Cl: 83.56%

• Ca: 46.11%; Cl: 63.88%

What is the percent composition of S in the formula (NH₄)₂S ?

• 12.05%
• 19.30%
• 47.11%
• 56.18%

A chemist places 2.50 g of iron on a scale. How many moles of iron are on the scale?

• 139.6 moles

• 22.3 moles

• 0.764 moles

• 0.045 moles

Shivani measures out 6.0 moles of epsom salt (MgSO₄) to put in her bath. How many grams of MgSO₄ went in the bath?

• 20 g

• 720 g

• 0.050 g

• 340 g

A recipe calls for 12 g of baking soda, NaHCO₃. How many moles of NaHCO₃ go into the recipe?

• 0.058 moles

• 7.0 moles

• 0.14 moles

• 3.4 moles

How many molecules are in 2.50 mol of NaCl?

• 1.50 x10²⁴ molecules

• 1.50 molecules

• 4.15 molecules

• 1.51 x10²⁴ molecules

Calculate the number of atoms in 0.0340 g Zn.

• 5.200 x 10^-4 atoms Zn
• 3.130 x 10²³ atoms Zn
• 3.130 x 10²⁰ atoms Zn
• 1 atom Zn

Determine the mass of 4.20 moles of C₆H₁₂

• 354 g

• 84 g

• 337 g

• 421 g

How many moles of sodium chloride are in a 321.8 g sample?

• 18810 moles

• 3.315 x 10²⁴ moles

• 5.507 moles

• 4.767 moles