Question

4 molar solution of NaOH contains :

• A. 160 g of NaOH dissolved in 1000 ml of water
• B. 160 g of NaOH present in 2 litres of water
• C. 80 g of NaOH present in 500 g of water
• D. 40 g of NaOH in 100 ml of water

Answer 1

Answer: (A), (C)

160 g of NaOH dissolved in 1000 ml of water
80 g of NaOH present in 500 g of water

$M=4$

Mol. weight of NaOH, $M_W=40$

If $V=1000ml$

$4=\frac{m\times 1000}{40\times 1000}$

$\Rightarrow m=160g$

If 500 g water is taken its volume $=$ 500 ml

$4=\frac{m\times 1000}{40\times 500}$

$\therefore m=80g$