Question

Two solutions of a substance (non electrolyte) are mixed in the following manner. 480ml of 1.5M first solution + 520mL of 1.2M second solution. What is the molarity of the final mixture?

(a) 1.20M 

(b) 1.50M

(c) 1.344M 

(d) 2.70M

Answer 1

(c) : Total millimoles of solute
= 480 × 1.5 + 520 × 1.2 = 720 + 624 = 1344.
Total volume = 480 + 520 = 1000.
Molarity of the final mixture = (1344)/(1000) =  1.344M.