Question

Find the molarity of the following solution:

734 grams of lithium sulfate (Li2SO4) is dissolved to make 2.5 liters of solution.

Answer 1

Answer:

2.67 M

Explanation:

Molarity, which is the molar concentration of a substance, can be calculated using the formula;

M = n/V

Where;

M = molarity (M)

n = number of moles (mol)

V = volume (Litres)

Based on the provided information in this question, mass of lithium sulfate (Li2SO4) = 734g, volume = 2.5L

Using mole = mass/molar mass

Molar mass of Li2SO4 = 7(2) + 32 + 16(4)

= 14 + 32 + 64

= 110g/mol

Mole = 734/110

Mole (n) = 6.67moles

Molarity = n/V

Molarity = 6.67/2.5

Molarity = 2.668

Molarity of Li2SO4 in the solution is 2.67 M

Answer 2

Answer:

The molarity of the solution is 2.672$\frac{moles}{liter}$

Explanation:

Molarity (M) is a way of expressing the concentration of solutions. It is defined as the number of moles of solute per volume of solution. The Molarity of a solution is determined by the following expression:

$Molarity=\frac{number of moles}{volume}$

Molarity is expressed in units $\frac{moles}{liter}$.

Being the molar mass of Li₂SO₄ 109.94 g/mol, then you can apply the following rule of three: if 109.94 grams are present in 1 mole, 734 grams will be present in how many moles?

$amount of moles=\frac{734 grams*1 mole}{109.94 grams}$

amount of moles= 6.68 moles

Then:

• number of moles= 6.68 moles
• volume= 2.5 L

Replacing in the definition of molarity:

$Molarity=\frac{6.68 moles}{2.5 L}$

and solving you get:

Molarity= 2.672$\frac{moles}{liter}$

The molarity of the solution is 2.672$\frac{moles}{liter}$