Question

Question 2
Calculate the formula unit masses of $ZnO,N{a}_{2}O,K_{2}C{O}_3$. Given atomic masses of Zn = 65 u, Na = 23 u, K = 39 u, C = 12 u, and O = 16 u.

Answer 1

i) Formula unit mass of ZnO = Atomic mass of Zn + Atomic mass of O
= 65 + 16
= 81 u
ii) Formula unit mass of $N{a}_{2}O=2\times AtomicmassofNa+AtomicmassofO$
$=2\times 23+16$
= 62 u
iii) Formula unit mass of $K_{2}C{O}_3=2\times AtomicmassofK+AtomicmassofC+3\times AtomicmassofO$
$=2\times 39+12+3\times 16$
= 138 u