Question

What volume of 1.5M NaCl is needed for a reaction that requires 146.3g NaCl?

Answer 1

Explanation:

146.3g NaCl (mol NaCl/58.44g NaCl) = 2.50 mol NaCl

1.5M NaCl = 1.5 mol NaCl / 1 L = 2.5 mol NaCl / x L, solve for x

x L = 2.5 mol NaCl / 1.5 mol NaCl = 1.66 L

It gives the answer and all the working.

To put it another way:

Dividing the amount required by the molar mass

we quickly see that 2.5 moles are required.

One litre of 1.5 molar solution gives 1.5 moles

we need a further mole, which is 2/3 of 1.5 so 2/3 of a litre.

First you need to convert your grams to moles so:

146.3g NaCl/58.44g NaCl = 2.50 Moles of NaCl

Next you need to use your conversion method which is:

Morality = Moles of Solutes / Liters of Solution

3.00 M NaCl = 2.50 Mol NaCl / x

2.50 Mol NaCl / 3.00 M NaCl = 0.833 L of solution

146.3g NaCl (mol NaCl/58.44g NaCl) = 2.50 mol NaCl

1.5M NaCl = 1.5 mol NaCl / 1 L = 2.5 mol NaCl / x L, solve for x

x L = 2.5 mol NaCl / 1.5 mol NaCl = 1.66 L