Unit 9 Practice Test: The Mole

What is the molar mass of AuCl₃?

• 96.5 g

• 130.5 g

• 232.5 g

• 303.5 g

A mole of carbon dioxide contains 6.02 x 10²³ _____.

• atoms
• formula units
• ions
• molecules

How many grams of NaCl are in 11.00 moles?

• 0.4500 g

• 156.6 g

• 331.0 g

• 643.5 g

What is the percent composition of barium in BaCrO₄?

• 20.5%

• 54.2%

• 25.26%

• 66.88%

How many moles are in 5.0 L of Ar gas (at STP)?

• 112 mol

• 8.92 mol

• 0.223 mol

• 2.80 mol

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

Which represents the greatest number of atoms?

• 50.0 g Cs
• 50.0 g Co
• 50.0 g Ca
• 50.0 g Cu

Which of the following statements regarding the mole is INCORRECT?

• A mole is a unit of quantity equal to 6.02 x 10²³ particles.

• The number of particles in a mole is known as Avogadro’s number.

• A mole of particles of an element is numerically equal to the atomic mass of the element.

• Equal moles of elements have the same mass in grams.

The mass of one mole of an element is equal to

• its atomic number from the periodic table, but in amus.

• its atomic mass from the periodic table, but in amus.

• its atomic mass from the periodic table, but in grams.

• its atomic number from the periodic table, but in grams.

Calculate the number of atoms in 0.0340 g Zn.

• 5.20 x 10^-4 atoms Zn

• 3.13 x 10²³ atoms Zn

• 3.13 x 10²⁰ atoms Zn

• 2.05 x 10²² atoms Zn