Question

If 2 L, 4 L and 6 L of three separate solutions of concentrations 1 M, 2 M and 3 M, respectively, are mixed together then what is the concentration of the resultant mixture?

(a) 2.333 M

(b) 6.000 M

(c) 3.333 M

(d) 1.500 M

This question was posed to me in final exam.

This question is from Expressing Concentration of Solutions in chapter Solutions of Chemistry – Class 12

Answer 1

Correct option is (a) 2.333 M

The explanation is: Given,

V1 = 2 L

V2 = 4 L

V3 = 6L

M1 = 1 M

M2 = 2 M

M3 = 3 M

Resultant concentration, MR = (M1V1 + M2V2 + M3V3)/(V1 + V2 + V3)

MR = ( 2 x 1 + 4 x 2 + 6 x 3 )/( 2 + 4 + 6) = 2.333 M.