Question

If 1 M and 2.5 litre NaOH solution is mixed with another 0.5 M and 3 litre NaOH solution, then molarity of the resultant solution will be.

• A. 1.0 M
• B. 0.73 M
• C. 0.80 M
• D. 0.50 M

Answer 1

Answer: (B)

0.73 M

Answer 2

$( 2.5 \times 1 + 3 \times 0.5 ) = M _ { 3 } \times 5.5$

or $2.5 + 1.5 = M _ { 3 } \times 5.5$ or $M _ { 3 } = \frac { 4 } { 5.5 } = 0.73$M.