Question

25g of NaCl is dissolved in water. The solution was found to weigh 125g. Calculate the mass percentage of NaCl in the solution.​

Answer 1

Answer:

I have never heard of a concept called “mass concentration” of a solution, but I am guessing it refers to “percent by mass” or “mass percent”. If that’s what OP means, then ….

Percentages (from way back in middle school math or earlier) is always (for all values of always):

percent blurf = quantity of blurftotal quantity×100

So for percent by mass, both quantities are expressed as mass, and it’s the mass of NaCl divided by the total mass of the solution, then times 100%

mass % NaCl = 25 g150 g+25 g×100

mass %NaCl = 14.3%