10.
Seema took three solids, A, B and C and made their saturated solutions in 100 g water at different
temperatures. The amounts of A, B and C used to form saturated solutions are shown in the table:
t
Solute
Temperature in K
313 K
333 K
353 K
293 K
37 g
38 g
36 g
35 g
a
106 g
167 g
b
32 g
62 g
40 g
46 g
54g
34 g
What are the amounts of A, B and C needed to form saturated solutions at 293 K? What
can you conclude based on this observation?
Calculate the amount of solutes A, B and C needed to form saturated solutions in 500g
water at 313 K.
(111)
Find the concentration in mass percent of A and C at 353 K.
Answers
Explanation:
(a) At 313 K 62 g of potassium nitrate dissolved in 100 g of water. So to produce a saturated solution of potassium nitrate in 50 g of water we need
100
62
×50=31 g of potassium nitrate.
(b)Some soluble potassium chloride will separate out in the form of crystal at room temperature because the solubility of potassium chloride will decrease.
(c)
(i) Solubility of Potassium nitrate at 293 K is 32 g.
(ii) Solubility of sodium chloride at 293 K is 36 g.
(iii) Solubility of Potassium chloride at 293 K is 35 g.
(iv) Solubility of Ammonium chloride at 293 K is 37 g.
The solubility of Ammonium chloride is highest at this temperature.
(d)The solubility of salt increases with the increase in temperature.