UNIT – 06 (STOICHIOMETERY)

The empirical formula represents:

• The actual number of atoms in a molecule

• The simplest whole-number ratio of atoms

• The structural arrangement of atoms

• The physical properties of a compound

The empirical formula of benzene (C6H6) is:

• C2H2

• CH

• C6H6

• CH3

The molecular formula of hydrogen peroxide is:

• H2O

• HO

• H2O2

• H3O

If a compound has a carbon-to-hydrogen ratio of 2:6, its empirical formula is:

• C2H6

• CH3

• CH6

• CH2

A compound with molecular formula C6H12O6 has an empirical formula of:

• CH2O

• C6H6O6

• C3H6O3

• C2H4O2

Molecular mass is determined by:

• The sum of atomic numbers

• The sum of atomic masses in a molecule

• The number of molecules present

• The number of isotopes present

The molecular mass of water (H2O) is:

• 18 amu

• 20 amu

• 16 amu

• 10 amu

The molecular mass of glucose (C6H12O6) is:

• 180 amu

• 120 amu

• 90 amu

• 150 amu

The formula mass of NaCl is:

• 48.5 amu

• 58.5 amu

• 60 amu

• 70 amu

The formula mass of KClO3 is:

• 100 amu

• 112 amu

• 122.5 amu

• 132 amu