Pragya tested the solubility of four 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 $100 \,g$ of water to form a saturated solution).
Substance Dissolved $283 \,K$ $293 \,K$ $313 \,K$ $333 \,K$ $353 \,K$
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 $50 \,g$ 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.

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(N/A) According to the table,the solubility of potassium nitrate at $313 \,K$ is $62 \,g$ per $100 \,g$ of water.
To find the mass needed for $50 \,g$ of water:
Mass $= (62 \,g / 100 \,g) \times 50 \,g = 31 \,g$.
Thus,$31 \,g$ of potassium nitrate is required.
$(b)$ As the solution cools,Pragya will observe the formation of crystals of potassium chloride. This occurs because the solubility of most solid solutes in water decreases as the temperature decreases. When the solution cools,it becomes supersaturated,and the excess solute crystallizes out of the solution.

Explore More

Similar Questions

$(a)$ Give any one point of difference between true solution,colloidal solution,and suspension.
$(b)$ $20 \, g$ of sodium chloride is dissolved in $100 \, mL$ of water. How will you test whether the given solution is saturated or unsaturated at the given temperature?
$(c)$ Suggest any one method by which we can increase the solubility of saturated solutions.

Difficult
View Solution

What volume of ethyl alcohol and water must be mixed together to prepare $250 \, mL$ of $60 \%$ by volume of alcohol in water?

Why does a mixture not have a fixed melting or a fixed boiling point?

You are given two samples of water labelled as $A$ and $B$. Sample $A$ boils at $100\,^{\circ}C$ and sample $B$ boils at $102\,^{\circ}C$. Which sample of water will not freeze at $0\,^{\circ}C$? Comment.

Sidak took $50\, mL$ of water in two beakers at room temperature and added sodium chloride to one beaker while sugar to the other,until no more solute could be dissolved. Then she heated the contents of the beakers and added more solutes in them.
$(a)$ Will the amount of salt and sugar that can be dissolved in water at a given temperature be the same?
$(b)$ What would you expect to happen if she cools the contents of the beakers? Justify your answer.

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo