U3: Percent Composition: Mastery Test

Select the correct answer. 294 g of potassium dichromate contains 52 g of chromium and 39 g of potassium. What is the mass percent of oxygen in the compound?

• A. 69.047%

• B. 38.095%

• C. 17.687%

• D. 13.265%

Select the correct answer. Allicin contains 59.9 g of carbon, 21.7 g of hydrogen, 24.4 g of oxygen, and sulfur. What is the mass percent of sulfur in a 162 g sample of the compound?

• A. 13.40%

• B. 15.06%

• C. 34.57%

• D. 36.98%

Select the correct answer. What is the mass percent of nitrogen in ammonium carbonate, (NH₄)₂CO₃?

• A. 12.50%

• B. 14.58%

• C. 29.16%

• D. 49.95%

Select the correct answer. A compound contains 14.5 g of magnesium and 3.5 g of oxygen. What is the mass percent of oxygen in the compound?

• A. 24.14%

• B. 19.44%

• C. 61.11%

• D. 80.56%

Tags

NGSS.HS-PS1-7

Select the correct answer. A compound weighing 115 g contains 68.3 g of carbon, 13.2 g of hydrogen, 15.9 g of nitrogen, and some amount of oxygen. What is the mass percent of oxygen in the compound?

• A. 11.48%

• B. 15.30%

• C. 13.83%

• D. 13.91%

Select the correct answer. What is the mass percent of hydrogen in ammonium phosphate, (NH₄)₃PO₄?

• A. 42.93%

• B. 28.19%

• C. 20.77%

• D. 8.11%

Select the correct answer. A compound is formed when 171.2 g of carbon reacts with 28.8 g of hydrogen. What is the mass percent of hydrogen in the compound?

• A. 14.4%

• B. 28.8%

• C. 75%

• D. 85.6%

Tags

NGSS.HS-PS1-7

Select the correct answer. What is the mass percent of oxygen in sodium bicarbonate (NaHCO₃)?

• A. 19.04%

• B. 27.37%

• C. 38.09%

• D. 57.13%

Select the correct answer. What is the percentage of lithium in lithium carbonate (Li₂CO₃)?

• A. 9.39%

• B. 16.25%

• C. 18.78%

• D. 21.65%

Select the correct answer. What is the mass percent of sodium in NaCl?

• A. 39.34%

• B. 60.66%

• C. 64.85%

• D. 78.68%

Tags

NGSS.HS-PS1-7