Question

Match the formula unit mass with the respective compounds

• A. 101u
• B. 78u
• C. 100u

Answer 1

(i) $N{a}^{+}{S}^{2–}$
$\Rightarrow N{a}_{2}S\Rightarrow$ 23 × 2 + 32 × 1
= 46 + 32
= 78 u
(ii) Potassium Nitrate
$K^{+}N{O}_3^{-}\Rightarrow KN{O}_3$
= 39 + 14 + 16 × 3
= 39 + 14 + 48
= 101 u
(iii) Calcium carbonate
$C{a}^{2+}C{O}_3^{2-}$
$CaC{O}_3$
= 40 + 12 + 16 × 3
= 40 + 12 + 48
= 100 u