Pragya tested the solubility of three di | Class 9 Science Chapter Is Matter Around Us Pure, Is Matter Around Us Pure NCERT Solutions

Question:

Pragya tested the solubility of three different substances at 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 Tem per atu re in K
  283 293 313 333 353
  Potassium nitrate 21 32 62 106 167
  Sodium chloride 36 36 36 37 37
  Potassium chloride 35 35 40 46 54
  Ammonium chloride 24 37 41 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?
(b) Pragya makes a saturated solution of potassium chloride in water at 353 K and leaves the solution to cool at room temperature. What would she observe as the solution cools? Explain.
(c) Find the solubility of each salt at 293 K. Which salt has the highest solubility at this temperature?
(d) What is the effect of change of temperature on the solubility of a salt?

Answer:

(a). 62 gm Potassium nitrate dissolved in 100 gm of water 

               62 / 2 = 31 gm 

       Potassium nitrate dissolved in 50 gm of water.

(b). In the given table, we see Potassium chloride solubility at different temperature then solubility was increased as the temperature was increased. An temperature decrease the solubility of Potassium chloride was decreased and the remains potassium chloride at higher lower temperature precipitate out.

(c). Ammonium chloride 

(d). Solubility was increased as the temperature was increased.


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Welcome to the NCERT Solutions for Class 9 Science - Chapter . This page offers a step-by-step solution to the specific question from Excercise 5 , Question 3: Pragya tested the solubility of three different substances at different temperatures and collected t....