# What is the molarity of a solution of ammonium chloride prepared by diluting 50.00 mL of a 3.79 M NH_4Cl solution to 2.00 L?

Jul 28, 2016

0.09475 moles per litre.

#### Explanation:

Use $M = \frac{n}{V}$

Where M is molarity in moles/litre, n is number of moles, and V is number of litres.

Rearrange for n: $n = M . V$ = 3.79 x 0.05 = 0.1895 moles.

After diluting, how many moles of solute will you have? Answer: The same. But now the solution volume will be 2 litres.

Therefore: $M = \frac{n}{V}$ = 0.1895 / 2 = 0.09475 mol/litre.

And if you want to make it even simpler - you are diluting 50 ml to 2000 ml, which is a dilution of 40 times.

So simply divide your starting molarity by 40. 3.79 divided by 40 is 0.09475.