Question

Question #70738

Answer 1

1.667 moles per litre

Explanation:

At the start you have 0.25 litre of 5M solution, so you have 0.25 x 5 = 1.25 moles of HCl.

At the end you have 0.25 + 0.5 = 0.75 litre of solution, and the number of moles of HCl is still 1.25.

So the new concentration or molarity is 1.25 / 0.75 = 1.667 M