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Unformatted text preview: --r CHM12 Solutions • MOLALITY
Mc'ality (m) = mole solute! Kg solvent ;. •
1. Calculate the molality of a HCI solution containing 21.2 g of HCI in 105 9
2. What mass of urea should be used in 205 g of water to obtain 0.55m of
\ • PPMlPPB
Ppm = mg solutel L solution
Ppb (g solutel 9 sample) x 109 SEATWORK:
1. Calculate the amount of water(in gr~ms) that must be added t010 grams of
urea to prepare 70% by mass of solution.
2. Calculate the molality of each of the following aqueous solutions:
a. 3.5M HCI solution with density of 1.2 gfml and Volume of solution is
to 75 ml
b. 65% by mass K2S04 and mass of solution is 200 g.
3. Concentrated sulphuric acid is 98% H2S04by mass. Calculate the molality
and molarity oftheacid solution if density is 1.83 gfml and mass of solution = i~
1. What is the ppm of mercury present if 0.02 gram of the metal is
measured in 800 ml of sample analyzed?
• CONVERSION BETWEEN CONCENTRATIONS
1. Calculate the molarity of a 0.45 m glucose solution if molar mass of
glucose is 180.2 g and density of solution is 1.16 g/ml. (l'I1a~S sol-en-t
2. The density of 1.5M aqueous ethanol is 0.87 g/ml. What is the molality
of the solution? ~/60\h ':;.SOm\) ~ro 3. -=~) 4. I .~is450g.
How would you prepare 500 ml of 0.8M HCI from 2.5 M HCI solution? (
a Calculate the molality of
~ass of aqueous phosphoric acid
of ~otv) -lSU.9} 4. Temperature
o Pressure of gaseous solutions
Effect of Temperature on Solubility
o Solubility of solid increases with temperature
of gasas in water decreaseSwith increa~ing,temperature
o Increase in Temperature favour endo~ennic process
Effects of Pressure on Solubility
o Explain Henry's Law
o Give examples
0 Using the solution in 3, what is the moiarity of the solution if density is
1.5 g/ml? PRINCIPLES OF SOLUBILITY
• The extent to which a solute dissolves in a particular solvent depends on the
o Nature of solvent and solute
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