Chapter 5: Chemical Quantities

In determining atomic mass units, the standard is the

• carbon-12 atom.

• hydrogen-1 atom.

• carbon-14 atom.

• oxygen-16 atom.

The atomic mass unit is used to express

• atomic mass.

• atomic number.

• atomic mass number.

• molar mass.

The unit g/mol is the unit of

• atomic mass.

• atomic number.

• molar mass.

• atomic mass number.

The number of atoms in a mole of any element is called

• its atomic number.

• the molar mass number.

• Avogadro’s number.

• the gram-atomic number.

Using a periodic table, find the identity of the element that has an atomic mass of 40.078 amu.

• C

• Ca

• Cr

• Cu

Using a periodic table, determine which of the following quantities is not equal to 1.00 mole.

• 6.02 x 10^23 carbon atoms

• 79.9 g Br

• 26.0 g Fe

• 65.4 g Zn

Avogadro’s number is

• 6.022 x 10^23

• 3.1416

• 1.602 x 10^-24

• 3.0 x 10^-8

The molar mass of an element is numerically equal to the

• element’s atomic mass.

• number of neutrons found in the element.

• element’s atomic number.

• mass of one atom of the element.

What is the molar volume of a gas at standard temperature and pressure (STP)?

• 1.0 atm/mol

• 22.4 L/mol

• 1.0 L/22.4 mol

• 22.4 atm/mol

_____ gives the actual number of atoms in the structure of the molecule, as opposed to just the ratio.

• empirical formula

• density

• molecular formula

• percent composition