To a 4 L of 0.2 M solution of NaOH, 2L of 0.5 M NaOH are added. The molarity of the resulting solution is :

Options

A. 0.7 M
B. 0.3 M
C. 1.8 M
D. 1.18 M

Answer

B

Explanation

Moles of NaOH in 4 L solution `=0.2xx4=0.8`
Moles of NaOH in 2 L solution `=0.5xx2=1.0`
Total moles `=1.0+0.8=1.8`
Total volume of solution `=4+2=6L`
Molarity `=(1.8)/(6)=0.3` M