Question

How many liters of a 0.5 m sodium hydroxide solution would contain 2 moles of solute?

Answer 1

Answer:

• 4 liters

Explanation:

1) Data:

a) M = 0.5 M

Note: since the question is about volume (liters) and moles of solute, the correct unit for the concentration of the hydroxide solution is M (upper case) which is the unit for molarity. Lower case m is used for molality, and you cannot calculate the volume of the solution unless you know some other data, e.g. density of the solution.

b) n = 2

c) V (in liters) = ?

2) Formula:

Molarity is the number of moles of solute per liter of solution:

• M = n / V (in liters)

3) Solution:

a) Clear V from the formula: V (in liters) = M / n

b) Substitute: V (in liters) =  2 moles /  0.5M  = 4 liters ← answer