Question

What mass (in g) of NaCl is needed to prepare 1.5 L of a 3.0 M salt water solution?

Answer 1

263.2g are required.

The number of moles of NaCl in 1.5L of a 3.0M solution `=1.5xx3.0=4.5`

Using:

`A_rNa=23`

`A_rCl=35.5`

`M_rNaCl=23+35.5=58.5`

So 1 mole NaCl weighs 58.5g

So the weight of 4.5 moles = 4.5 x 58.5 = 263.25g

Answer 2

The formula that you will use is:
Grams = Molarity X liters X formula mass of solute

So for your problem:
grams = 3 X 1.5 X 58