Question:
Write the formulae for the following and calculate the molecular mass for each one of them.
(a) Custic potash
(b) Baking powder
(c) Lime stone
(d) Caustic soda
(e) Ethanol
(f) Common salt.
Solution:
(a) $\mathrm{KOH}=39+16+1=56 \mathrm{u}$
(b) $\mathrm{NaHCO}_{3}=23+1+12+3 \times 16=84 \mathrm{u}$
(c) $\mathrm{CaCO}_{3}=12+12 \times 3 \times 16=100 \mathrm{u}$
(d) $\mathrm{NaOH}=23+16+1=40 \mathrm{u}$
(e) $\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}=2 \times 12+6 \times 1+16=46 \mathrm{u}$
(f) $\mathrm{NaCl}=23+35.5=58.5 \mathrm{u}$