SCH3U Unit 2 Quiz

A compound is found to contain 63.52% iron and 36.48% sulfur. What is its empirical formula?

• Fe2S3

• FeS2

• FeS

• Fe3S2

A laboratory sample contains 1.05 grams of nickel and 0.29 grams of oxygen. What is the empirical formula?

• NiO

• Ni2O3

• NiO2

• Ni2O

Calculate the % composition for Mg(OH)2.

• Mg: 41.7%, O: 54.9%, H: 3.4%

• Mg: 60.3%, O: 30.1%, H: 9.6%

• Mg: 24.3%, O: 70.6%, H: 5.1%

• Mg: 50.0%, O: 40.0%, H: 10.0%

What is the empirical formula for a compound if a 2.50 g sample contains 0.900 g of calcium and 1.60 g of chlorine?

• CaCl2

• CaCl

• Ca2Cl

• Ca2Cl3

Calculate the % composition for potassium sulfate.

• K = 44.88%, S = 18.39%, O = 36.73%

• K = 39.10%, S = 22.56%, O = 38.34%

• K = 50.00%, S = 20.00%, O = 30.00%

• K = 29.00%, S = 32.00%, O = 39.00%

A compound is 85.7 % carbon and 14.3 % hydrogen. What is the empirical formula?

• CH2

• C2H6

• CH4

• C2H2

What is the percent composition of Ca(OH)₂?

• Ca: 54.09%, O: 43.20%, H: 2.70%

• Ca: 40.08%, O: 45.00%, H: 14.92%

• Ca: 60.00%, O: 30.00%, H: 10.00%

• Ca: 50.00%, O: 40.00%, H: 10.00%

What is the percent composition of Na₃PO₄?

• Na: 42.07%, P: 18.89%, O: 39.04%

• Na: 32.00%, P: 21.00%, O: 47.00%

• Na: 50.00%, P: 15.00%, O: 35.00%

• Na: 40.00%, P: 20.00%, O: 40.00%

Determine the empirical formula of a compound containing 63.50% silver, 8.25% nitrogen, and the remainder oxygen.

• AgNO₃ (Silver nitrate, AgNO₃)

• AgNO₂ (Silver nitrite, AgNO₂)

• AgN₂O (Silver nitride oxide, AgN₂O)

• Ag₂NO₃ (Disilver nitrate, Ag₂NO₃)

A compound is found to contain 63% manganese, Mn, and 37% oxygen. What is the compound's empirical formula?

• MnO₂

• MnO

• Mn₂O₃

• MnO₃