Question

The percent concentration of a solution is a ratio of the amounts of dissolved solute and solution, expressed as a percentage. The percent concentration of a solution can be written generally as

%concentration=amountofsoluteamountofsolution×100%

Depending on the situation, a percent concentration might be calculated for mass/mass, volume/volume, or mass/volume.

A.) Calculate the mass percent of a solution that is prepared by adding 27.6 g of NaOH to 421 g of H2O.

Express your answer numerically.

B.)

Calculate the mass/volume percent of a NaCl solution in which 173 g of NaCl is dissolved in enough water to give a total volume of 4.53 L .

Express your answer numerically.

Answer 1

A. mass of solute ( NaOH) = 27.6g

mass of solution = mass of solute + mass of solvent

                            = 27.6 + 421   = 448.6g

the mass percent of a solution = mass of solute *100/mass of solution

                                                     = 27.6*100/448.6   = 6.15%

B. mass of solute = 173g

total volume    = 4.53L   = 4530ml

the mass/volume percent     = 173*100/4530   = 3.82(m/v)%