Question

If 20 g NaOH is present in 500 ml aqueous solution then molarity of Na+ ions will be​

Answer 1

Answer:

Molarity of Na ions = 1 M

Explanation:

Molarity of Na ions = Molarity of NaOH solution ( strong electrolyte) = 1 M. Here M = Molarity of NaOH, m= molar mass of NaOH, V= volume of solution, w= mass of NaOH present in the solution.

Answer 2

Given:

20 g NaOH is present in 500 ml aqueous solution.

To find:

Molarity of Na+ ions?

Calculation:

First let's calculate moles of NaOH:

$\rm \: moles = \dfrac{given \: mass}{molar \: mass}$

$\rm \implies\: moles = \dfrac{20}{40}$

$\rm \implies\: moles = 0.5$

Now, 0.5 moles of NaOH on dissociation will give 0.5 moles of Na+ ions (considering complete dissociation).

$\rm \implies \: molarity = \dfrac{moles}{volume}$

$\rm \implies \: molarity = \dfrac{0.5}{ (\frac{500}{1000} )}$

$\rm \implies \: molarity = \dfrac{0.5}{0.5}$

$\rm \implies \: molarity = 1 M$

So, molarity of Na+ ions is 1 M.