##
Calculate the molecular masses of H
_{
2
}
, O
_{
2
}
, Cl
_{
2
}
, CO
_{
2
}
, CH
_{
4
}
, C
_{
2
}
H
_{
6
}
, C
_{
2
}
H
_{
4
}
, NH
_{
3
}
, CH
_{
3
}
OH

**
Answer
**

Atomic mass of H =1 u

Atomic mass of O = 16 u

Atomic mass of Cl = 35.5 u

Atomic mass of C = 12u

Atomic mass of N= 14 u

**
Molecular mass of H
**
_{
2
}
= 2 x Atomic mass of H

= 2 x 1u

=
**
2u
**

**
Molecular mass of O
**
_{
2
}
= 2 x Atomic mass of O

= 2 x 16u

=
**
32u
**

**
Molecular mass of Cl
**
_{
2
}
= 2 x Atomic mass of Cl

= 2 x 35.5u

=
**
71u
**

**
Molecular mass of CO
**
_{
2
}
= 1x Atomic mass of C + 2 x Atomic mass of O

= 1 x 12u + 2x16u

= 12u+32u

=
**
48u
**

**
Molecular mass of CH
**
_{
4
}
= 1x Atomic mass of C + 4 x Atomic mass of H

= 1 x 12u + 4x1u

= 12u+4u

=
**
16u
**

**
Molecular mass of C
**
_{
2
}
**
H
**
_{
6
}
= 2x Atomic mass of C + 6 x Atomic mass of H

= 2 x 12u + 6x1u

= 24u+6u

=
**
30u
**

**
Molecular mass of C
**
_{
2
}
**
H
**
_{
4
}
= 2x Atomic mass of C + 4 x Atomic mass of H

= 2 x 12u + 4x1u

= 24u+4u

=
**
28u
**

**
Molecular mass of NH
**
_{
3
}
= 1x Atomic mass of N + 3 x Atomic mass of H

= 1 x 14u + 3x1u

= 14u+3u

=
**
17u
**

**
Molecular mass of CH
**
_{
3
}
**
OH
**
= 1x Atomic mass of C + 4 x Atomic mass of H + 1 x Atomic mass of O

= 1 x 12u + 4x1u + 1 x 16u

= 12u+4u+16u

=
**
32u
**