Question #63908
1 Answer
Your solution contains 0.32 g of sodium chloride.
A percent concentration by mass expresses the ratio between the mass of the solute, in your case sodium chloride, and the total mass of the solution, multiplied by 100.
So, you know that your sample weighs 16 g and that it's 2% m/m sodium chloride. You can use this data to determine how many grams of sodium chloride must be present in that much solution by
Think of it like this: you know the mass of sodium chloride represents 2% by mass of a solution. To get from 2% to 100% you need to multiply by 50, so the mass of sodium chloride can be determined by dividing the total mass by 50.
For example, if you have a 25% m/m solution that has a total mass of 16 g, the mass of sodium chloride would be 4 g.
That happens because you need to divide 100% by 4 to get to 25%, so divide the total mass by 4 to get the mass of the solute.