# What is the mass of #NaCl# required to prepare 0.5 liters of a 2.5 molar solution of #NaCl#?

##### 1 Answer

73 g

#### Explanation:

The molecular weight of NaCl is 58.44 g/mol

So, one mole of NaCl weighs 58.44 g.

A 2.5 M solution is 2.5 moles per liter (Molarity is just the number of moles per liter).

Therefore, 0.5 L would contain 1.25 mol. Hence, you would need 1.25 × 58.44 g = 73 g.

As equations:

So,

Substitute for moles

We need

Put in the numbers:

Personally, I prefer the first approach!

You can find out more about moles and molarity here.