Question

a solution was made by dissolving 5.00 g Nacl in 100.0 g of h2O

Answer 1

Answer:

There are several ways of expressing the concentration of a solution by using a percentage. The mass/mass percent (% m/m) is defined as the mass of a solute divided by the mass of a solution times 100:

%m/m=massofsolutemassofsolution×100%(13.5.1)

mass of solution = mass of solute + mass solvent

If you can measure the masses of the solute and the solution, determining the mass/mass percent is easy. Each mass must be expressed in the same units to determine the proper concentration.

Suppose that a solution was prepared by dissolving 25.0g of sugar into 100.0g of water.

The mass of the solution is

mass of solution = 25.0g sugar + 100.0g water = 125.0 g

The percent by mass would be calculated by:

Percent by mass=25.0g sugar125.0g solution×100%=20.0%sugar(13.5.2)