Question

Calculate the molarity of a solution containing 16 gm of NaOH in 400 cc(or ml) of solution (M.M. of NaOH = 40amu)

Answer 1

Answer:-

The Required Answer Is 1 M or 1 mole per liter.

Explanation:-

Given:-

• Mass of NaOH (Sodium Hydroxide) = 16 gm.

• Molecular masd of NaOH = 40 amu.

• Volume of solution = 400 cc or ml.

To Find:-

• The molarity of the solution.

Formula Used:-

$\orange{\longrightarrow\boxed{\pink{\bf M = \dfrac{N}{V}.}}}$

And

$\orange{\longrightarrow\boxed{\pink{\bf N = \dfrac{m}{M.M.}.}}}$

Where,

• M = Molarity.

• N = Number of moles.

• V = Volume of solution in liters.

• m = Mass of the element.

• M.M. = Molecular Mass of the element.

So Here,

• M = ?? [To Find].

• N = ?? [Unknown].

• V = $\tt\dfrac{400}{1000}\:\:L = 0.4\:\:Liters$

• m = 16 gm.

• M.M. = 40 amu.

So Now,

Number of moles in 16 gm of NaOH,

$\tt= \dfrac{m}{M.M.} moles\\ \\ \tt = \cancel\frac{16}{40} \: \: moles. \\ \\ \bf= 0.4 \: \: Moles$

Therefore Molarity,

$\rm = \dfrac{N}{V} \: M. \: \: \: \: \\ \\ \tt = \cancel\frac{0.4}{0.4} \: M \: \: \: \\ \\ \large \red{ \boxed{ \blue{ \bf= 1 \: M.}}}$

$\bf\therefore$ Molarity of the solution is 1 M or 1 mole per liter.