Calculate the molecular masses of the following:

(a) Hydrogen, H2


(b) Oxygen, O2


(c) Chlorine, Cl2


(d) Ammonia, NH3


(e) Carbon dioxide, CO2


(Atomic masses: H = 1 u; O = 16 u; Cl = 35.5 u; N = 14 u; C = 12 u)

(a) Molecular mass of Hydrogen (H2) = 2 x H = 2 x 1 u = 2 u

(b) Molecular mass of oxygen (O2) = 2 x O = 2 x 16 u = 32 u


(c) Molecular mass of chlorine (Cl2) = 2 x Cl = 2 x 35.5 = 71 u


(d) Molecular mass of Ammonia (NH3) = 1 x N + 3 x H = 14 + 3 = 17 u


(e) Molecular mass of carbon dioxide (CO2) = 1 x C + 2 x O = 12 + 32 = 44 u


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