Question

The total number of electrons present in $18mL$ water (density $1g/mL$) is:

• A. $6.023\times {10}^{23}$
• B. $6.023\times {10}^{24}$
• C. $6.023\times {10}^{25}$
• D. $6.023\times {10}^{21}$

Answer 1

The correct option is B $6.023\times {10}^{24}$

Mass $=18g$ ($\because m=v\times d$)

Number of molecules of $H_{2}O$ in $18g$ mass

$=6.023\times {10}^{23}$

Number of electrons in $18g$ water

$=6.023\times {10}^{23}\times 10$

$=6.023\times {10}^{24}$

Hence, the correct option is $\text{B}$