9-2 Mass and Moles

Multiple Choice

What is the significance of mole conversions in chemistry?

• They help in measuring temperature

• They relate mass to the number of particles

• They are used to calculate pressure

• They determine the volume of gases

Multiple Choice

How many atoms are in 31.1 g of gold (Au)?

• 0.158 mol Au

• 9.51 × 10^22 atoms Au

• 196.97 g Au

• 6.02 × 10^23 atoms Au

Multiple Choice

What is the mass of 5.50 × 10²² atoms of helium (He)?

• 0.0914 g He

• 0.366 g He

• 4.00 g He

• 6.02 g He

Multiple Choice

Which of the following dimensional analysis setups will correctly convert 4.00x10²³atoms of cobalt to moles of cobalt? How many moles of colbalt are there?

• setup B : 0.6644mol Co
• setup A: 2.41x10⁴⁷mol Co
• setup A : 0.664mol Co
• setup B: 2.41x10⁴⁷mol Co

Multiple Choice

What is the mass of 3.01 × 10^23 atoms of sodium (Na)?

• 23 g

• 46 g

• 69 g

• 92 g

Multiple Choice

How many atoms are in 15.0 g of carbon (C)?

• 7.5 x 10^23 atoms

• 1.2 x 10^24 atoms

• 1.5 x 10^23 atoms

• 3.0 x 10^24 atoms

Multiple Choice

Calculate the number of moles of Al in 4.85 x 10^22 atoms of Al.

• 1.00 mol Al

• 2.17 g Al

• 0.726 mol Al

• 4.85 x 10^22 atoms Al