Q.
20 mL of 2 M NaOH solution is added to 400 mL of 0.5 M NaOH solution. The final concentration of the solution is _______ ×10⁻² M. (Nearest integer)
Numerical Question
This is a numerical-answer question. The correct answer is shown below.
Explanation
[Solution by Dr. Abubacker] Moles of NaOH $=0.020\times2+0.400\times0.5=0.04+0.20=0.24$ mol in $0.420$ L. $M=\frac{0.24}{0.42}=0.571=57.1\times10^{-2}$ M, i.e. 57. Answer: 57.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.