Mole Calculations and Mass Percent

What is the molar mass of AuCl₃?

• 96.55 g

• 130.00 g

• 232.50 g

• 303.32 g

A mole of carbon dioxide contains 6.02 x 10²³ _____.

• atoms
• formula units
• ions
• molecules

Which of the following would have more mass?

• 1 mole of Li
• 1 mole of Au
• 1 mole of Si
• None, all are equal

What is the molar mass of MgCl₂?

• 24.31 g/ml
• 95.21 g/mol
• 59.76 g/mol
• 70.90 g/mol

Determine the mass of 4.20 moles of C₆H₁₂ (Gram formula mass = 84.2 g/mole)

• 354 g
• 84 g
• 337 g
• 421 g

Vitamin C, also known as ascorbic acid, is water soluble and cannot be produced by the human body. Each day, a person's diet should include a source of Vitamin C, such as orange juice. Ascorbic acid has a molecular formula of C₆H₈O₆ and a molar mass of 176 grams per mole.

Determine the number of moles of vitamin C in an orange that contains 0.171 grams of vitamin C.

• 1.00 mole

• .005 mole

• .0010 mole

• .000972 mole

The element boron, a trace element in Earth's crust, is found in foods produced from plants. Boron has only two naturally occurring stable isotopes, boron-10 and boron-11. The sample of a green vegetable contains 0.0135 gram of boron. Determine the total number of moles of boron in the sample.

• 0.100 mol

• 0.010 mol

• 0.00125 mol

• 0.000125 mol

What is the mass percentage of Carbon in Carbon dioxide?

• 27.3%
• 42.9%
• 57.1%
• 72.7%

What is the percent by mass of magnesium in MgO?

• 20%
• 40%
• 50%
• 60%

What is the percent composition by mass of sulfur in the compound MgSO₄ (gram formula mass = 120 g/mol)?

• 20%
• 27%
• 46%
• 53%