Question

Find the number of valence electrons present in $0.53$ gram of $N{a}_{2}C{O}_3$.

• A. $3.01\times 10^{23}$
• B. $1.2046\times 10^{23}$
• C. $12.046\times 10^{23}$
• D. $6.023\times 10^{23}$

Answer 1

Answer: (B)

Total number of valence electron in $N{a}_{2}C{O}_3$
$=2\times 8+24=40$
$N{a}^{+}=8,C{O}_3^{2-}=24$
Number of valence electron in $106g$ of $N{a}_{2}C{O}_3$
$=40\times 6.023\times 10^{23}$
Number of valence electron in $0.53g$ of $N{a}_{2}C{O}_3$
$=0.2\times 6.023\times 10^{23}=1.2046\times 10^{23}.$