Question

a laboratory solution is made of water and ethylene glycol. How could one prepare 150 ml of a 40% ethylene glycol solution?

Answer 1

In this problem it is not clear whether 40% is by volume (v/v) or w/v %. So it is solved in both the ways.

V/V% means V mL of solute is present in 100 mL of the solution.

Volume of solute = V mL

Volume of solution = 100 mL

Volume of the solvent= (100-V) mL

W/V % means w g of solute is present in 100 mL of the solution.

Weight of the solute = w grams

Volume of the solution= 100 mL

Here we have assumed that volume of solution doesn't change after addition of the solute