Question

When 200. mL of water are added to 100. mL of 12% KCl solution the final concentration of KCl is ______.(Assume the volumes add)

a) 4.0%. b) 36%. c) 12%. d) 8.0%. e) 6.0%.

Answer 1

Answer:

The final concentration of KCl is 4%

Explanation:

This is a solution with KCl and water.

12% it's a way of concentration that indicates, that in 100 mL of solution, we have 12 g of solute.

If we add 200 mL to this solution, we also have 12 g of solute but now, we have to calculate the new concentration.

New volume = 100 mL + 200 mL → 300 mL

Let's make a rule of three

In 300 mL we have 12 g of solute

In 100 mL we have    (100 .12) / 300 = 4