Question

A 1.5 M solution of NaOH was made in a laboratory. If the solution made had a volume of 4.5 L, how many grams of NaOH were added?

Answer 1

270g

Step-by-step explanation:

Given parameters:

Concentration of solution = 1.5M

Volume of solution = 4.5L

Unknown:

Mass of NaOH added = ?

Solution:

Concentration is the number of moles of solute found in a solution.

To solve this problem, we need to find the number of moles of NaOH first;

Number of moles = concentration x volume

Number of moles = 1.5 x 4.5 = 6.75moles

Now, to find the mass of NaOH;

Mass of NaOH = number of moles x molar mass

Molar mass of NaOH = 23 + 16 + 1 = 40g

Mass of NaOH = 6.75 x 40 = 270g