Answer : The concentration of solution in percent by mass is 7.29 %
Explanation :
Percent by mass : It means that the mass of solute present in the mixture and multiply by 100.
Given:
Mass of KBr = 12.4 g
Mass of solution = 170 g
Now we have to calculate the concentration of solution in percent by mass.


Therefore, the concentration of solution in percent by mass is 7.29 %