3.
Pragya tested the solubility of three different substances a
different temperatures and collected the data as given below
(results are given in the following table, as grams of substance
dissolved in 100 grams of water to form a saturated solution
Substance Dissolved
Temperature in K
283 293 313 333
Solubility
353
21
32
62
106
167
36
Potassium nitrate
Sodium chloride
Potassium chloride
Ammonium chloride
36
36
37
37
35
35
40
46
54
37
55
66
(a) What mass of potassium nitrate would be needed to
produce a saturated solution of potassium nitrate in
50 grams of water at 313 K?
Answers
3.
Pragya tested the solubility of three different substances a
different temperatures and collected the data as given below
(results are given in the following table, as grams of substance
dissolved in 100 grams of water to form a saturated solution
Substance Dissolved
Temperature in K
283 293 313 333
Solubility
353
21
32
62
106
167
36
Potassium nitrate
Sodium chloride
Potassium chloride
Ammonium chloride
36
36
37
37
35
35
40
46
54
37
55
66
(a) What mass of potassium nitrate would be needed to
produce a saturated solution of potassium nitrate in
50 grams of water at 313 K?
Answer:
(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.