Question

How many grams of $NaOH$ should be added to water to prepare 250 ml solution of 2 M $NaOH$?

• A. $9.6\times {10}^3$
• B. $2.4\times {10}^3$
• C. $20$
• D. $24$

Answer 1

Answer: (C)

$20$

Let the weight of $NaOH$ added by $x$

$Moles=\frac{x}{40}=\frac{weight}{molecularweight}$

$Molarity=\frac{Molesofsolute\times 1000}{Volume\left(ml\right)}$

$⟹2=\frac{x\times 1000}{40\times 250}$

$⟹x=20$ $gm$