Chemistry Mole and Composition Quiz

Determine the number of atoms in 3.54 mol Mn.

• 2.13 x 10^24 atoms

• 4.13 x 10^24 atoms

• 2.13 x 10^23 atoms

• 4.13 x 10^23 atoms

Determine the number of molecules in 4.45 mol of C6H12O6.

• 2.68 x 10^23 molecules

• 2.68 x 10^24 molecules

• 4.45 x 10^24 molecules

• 6.02 x 10^23 molecules

Which has more mass, a mole of potassium or a mole of sodium?

• mole of sodium

• mole of potassium

• They have the same mass

• It depends on the temperature

A mixture contains 0.250 mol of Fe and 1.20 g of C. What is the total number of atoms in the mixture?

• 6.02 x 10^22 atoms

• 1.51 x 10^23 atoms

• 2.11 x 10^23 atoms

• 3.01 x 10^23 atoms

How many moles are in 0.500 g of Ba(OH)2?

• 0.00290 mol

• 0.00580 mol

• 0.00880 mol

• 0.0117 mol

How many moles of hydrogen atoms are present in 2.0 moles of ammonia NH3?

• 2.0 mol

• 3.0 mol

• 9.0 mol

• 6.0 mol

A compound contains 6.0 g of carbon and 1.0 g of hydrogen, and has a molar mass of 42.0 g/mol. What is the compound’s percent composition?

• C: 75.0%, H: 25.0%

• C: 85.7%, H: 14.3%

• C: 14.3%, H: 85.7%

• C: 66.7%, H: 33.3%

A compound contains 6.0 g of carbon and 1.0 g of hydrogen, and has a molar mass of 42.0 g/mol. What is the compound’s empirical formula?

• C₃H₆

• CH₄

• CH₂

• C₂H₄

A compound contains 6.0 g of carbon and 1.0 g of hydrogen, and has a molar mass of 42.0 g/mol. What is the compound’s molecular formula?

• CH₂

• C₂H₄

• C₃H₆

• C₆H₁₂

Chromium(III) nitrate forms a hydrate that is 40.50% water by mass. What is its chemical formula?

• Cr(NO₃)₃ · 3H₂O

• Cr(NO₃)₃ · 6H₂O

• Cr(NO₃)₃ · 9H₂O

• Cr(NO₃)₃ · 12H₂O