Question

The mole fraction of $NaCl$, in a solution containing 1 mole of $NaCl$ in 1000 g of water is:

• A. 0.0177
• B. 0.001
• C. 0.5
• D. 0.244

Answer 1

The correct option is A 0.0177

X=no. of moles of $NaCl=1$

Y=no. of moles of water$\left(H_{2}O\right)$ $=\frac{weight}{molecularmass}$ $=\frac{1000}{18}$ $=55.55$

Total number of moles$=55.55+1=56.55$

Mole fraction of $NaCl=\frac{no.ofmolesofNaCl}{no.ofmolesofsolution}$

$=\frac{1}{56.55}$

$=0.01768$

Hence, option $A$ is correct.