Chemistry Exam Review B

What is the volume, in liters, of 0.500 mol of CH gas at STP?

• 0.0335 L

• 11.2 L

• 16.8 L

• 22.4 L

How many atoms are in 3.5 moles of arsenic atoms?

• 5.8 x 10^-24 atoms

• 7.5 x 10^1 atoms

• 2.1 x 10^24 atoms

• 1.7 x 10^23 atoms

Which of the following sets of empirical formula, molar mass, and molecular formula is correct?

• CH, 78 g, C13H13

• CH4N, 90 g, C3H12N3

• CaO, 56 g, Ca2O2

• C3H8O, 120 g, C3H8O2

Avogadro's number of representative particles is equal to one ____.

• kilogram

• gram

• kelvin

• mole

The lowest whole-number ratio of the elements in a compound is called the ____.

• empirical formula

• molecular formula

• binary formula

• representative formula

What SI unit is used to measure the number of representative particles in a substance?

• kilogram

• ampere

• kelvin

• mole

Which of the following is NOT an empirical formula?

• C2N2H8

• C3H8O

• BeCr2O7

• Sb2S3

What is the molar mass of AuCl₃?

• 96 g

• 130 g

• 232.5 g

• 303.6 g

What is the percent composition of chromium in BaCrO4?

• 4.87%

• 9.47%

• 20.5%

• 25.2%

Which of the following is NOT true about empirical and molecular formulas?

• The molecular formula of a compound can be the same as its empirical formula.

• The molecular formula of a compound can be some whole-number multiple of its empirical formula.

• Several compounds can have the same empirical formula, but have different molecular formulas.

• The empirical formula of a compound can be triple its molecular formula.