Question

Calculate the molar concentration of ethanol in an aqueous solution that contains 2.3 g of ethanol in 3.5 l of solution

Answer 1

Explanation:

molecular mass of ethanol=46 g\mol

mass of solute=2.3 g

volume=3.5 l

no. of moles= 2.3/46=0.5 mol

molarity= 0.5/3.5=7 m

Answer 2

Given:

• The weight of ethanol = 2.3 g (46.07g/mol)
• The volume of the solution = 3.5 L

To Find:

• The molar concentration of ethanol.

Solution:

The amount of ethanol is given by,

⇒  2.30 g of ethanol × [ 1 mol of ethanol/46.07g ethanol] {canceling the like terms}

⇒ 2.30 × [1 mol of ethanol/46.07]  {dicide the terms in the bracket and multiply further}

⇒ 0.0499 g of ethanol is the amount of ethanol.

To find the molar concentration we should divide the amount by volume,

⇒ The molar concentration of ethanol = (0.0499 g of ethanol is the amount of ethanol)/3.5 L {dividing the terms}

⇒ The molar concentration of ethanol = 0.0142 g ethanol/L

⇒ The molar concentration = 0.0142 M

∴ The molar concentration of ethanol = 0.0142 M