In the laboratory, you have a molecular solid compound with a concentration of 20% m/m
by mass. Using this solution:

a) How can you prepare a 500g solution with a concentration of 25% m/m by mass, assuming
the solid compound is available in the laboratory?

b) How can you prepare a 500g solution with a concentration of 25% m/m by mass, assuming
that the solid compound is not available in the laboratory?

c) If the number of water molecules is 30 times greater than the number of solute molecules
in the solution with a concentration of 25% m/m, calculate the molar mass of the solute?