Question

A solution with a weight percentage of sodium hydroxide of 9% is prepared by adding the following mass of water (in grams) to 300 grams of that solution with a weight percent of $NaOH$ of 15%.

• A. 100 g
  
• B. 150 g
  
• C. 200 g
  
• D. 250 g
  

Answer 1

The correct option is C 200 g

15 = $\frac{NaOHweight}{\left(totalweight\right)}\times 100$

in this eqution total weight is 300gm so NaOH weight is 45 gm

in this question when x gm of water add in this solution we will get weight percent of NaOH is 9%

so the eqution is

9 =$\frac{45}{300+x}\times 100$

in sove this eqution x is 200gm

so the answer is 200gm

answer is C