Question

How many molecules of water are present in a $0.25mole$ of $H_{2}O$?

• A. $6.0\times {10}^{22}$
• B. $4.5\times {10}^{23}$
• C. $1.5\times {10}^{23}$
• D. $18\times {10}^{23}$

Answer 1

The correct option is C $1.5\times {10}^{23}$

$1mole$ of a compound has $6.023\times {10}^{23}$ molecules in it.

$\Rightarrow 1mole=$$6.023\times {10}^{23}$molecules

$0.25mole=x$molecules

$\Rightarrow x=\left(\frac{6.023}{4}\right)\times {10}^{23}$$=1.5\times {10}^{23}$ molecules of water.