Question

The total number of electrons present in 1.8 g of water is :

• A. $6.023\times {10}^{22}$
• B. $10.8576\times {10}^{23}$
• C. $10.8576\times {10}^{22}$
• D. $6.023\times {10}^{23}$

Answer 1

The correct option is D $6.023\times {10}^{23}$

We know that, 1 molecule of water consists of 10 electrons (2 electrons each of two hydrogen atoms and 8 electrons of one oxygen atom).
The number of molecules present in 1.8 g of water.
$18gof{H}_{2}O\stackrel{contains}{\to }6.023\times {10}^{23}molecules$
$\Rightarrow 1.8gof{H}_{2}Ocontains{}^{\prime }{x}^{\prime }molecules$
$x=\frac{1.8\times 6.023\times {10}^{23}}{18}$
$=\frac{6.023\times {10}^{23}}{10}=6.023\times {10}^{22}molecules$.
$\therefore$ Number of electrons in 1.8 g of water $=6.023\times {10}^{22}\times 10=6.023\times {10}^{23}$