(a) Calculate the % by mass of solute of the potassium perchlorate solution.
% w/w (or m/m) = (mass solute/mass solution)*100
mass solute = 8 g
mass solvent = 72 g
mass solution = 80 g
% w/w = (8/80)*100 = ?
(b) Calculate the mass/volume percent of the potassium perchlorate solution.
% (w/v)*100 or %(m/v) = ?
mass solution = 80 g
volume of solution = mass/density = 80/2.524 = ?
% m/v = ?
(c) Calculate the molar concentration of the potassium perchlorate solution.
M = #mols/L solution.
mols KClO4 = grams/molar mass = 8/molar mass = ?
You have mols and volume (volume from part b), solve for M.
d) Calculate the mole fraction of the solvent.
mols KClO4 you have from part c.
mols H2O = grams H2O/molar mass H2O = 72/18 = ?
Total mols = mols KClO4 + mols H2O = ?
Then mols solvent (H2O) = mols H2O/total mols = ?
(e) Calculate the molality of the potassium perchlorate solution.
m = mols KClO4/kg solvent
mols KClO4 you have from above in one of the othr parts.
kg solvent. 72 g H2O = 0.072 kg.
Solve for m.
Post your work if you get stuck.
Student A prepared a solution by dissolving 8.00 g potassium perchlorate in 72.0 g H2O. Given that the density of potassium perchlorate solution is 2.524 g/mL at 25 degree C .
(a) Calculate the % by mass of solute of the potassium perchlorate solution.
(b) Calculate the mass/volume percent of the potassium perchlorate solution.
(c) Calculate the molar concentration of the potassium perchlorate solution.
(d) Calculate the mole fraction of the solvent.
(e) Calculate the molality of the potassium perchlorate solution.
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