A 0.1539 molal aqueous solution of cane sugar (mol. mass = 342 g mol^–1) has a freezing point of 271 K while the freezing point of pure water is 273.15 K. What will be the freezing point of an aqueous solution containing 5 g of gluocose (mol. mass = 180 g mol^–1) per 100 g of solution?

Solution

Answer:

The molality of the cane sugar, m= 0.1539m
depression in freezing point $∆ T_{f}$ = 273.15-271
=2.15K

Since $∆ T_{f}$ = K_fm
or K_f = $∆ T_{f}$ /m = 2.15k/0.1539m = 13.97K/m

Now the weight of glucose , W₂ = 5g
molecular mass of glucose, M₂ =180g/mol

then $∆ T_{f}$ =K_fm

$∆ T_{f}$ =

$\frac{K_{f} \times W_{2} \times 1000}{W_{1} \times M_{2}} = \frac{13.97 \times 5 \times 1000}{100 \times 180} = 3.88 K$

then freezing point of solution = 273.15-3.88
=263.27K

Some More Questions From Solutions Chapter

Calculate the osmotic pressure in pascals exerted by a solution prepared by dissolving 1.0 g of polymer of molar mass 185,000 in 450 mL at 37⁰C.

Suppose a solid solution is formed between two substances, one whose particles are very large and the other whose particles are very small. What kind of solid solution is this likely to be?

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Solutions

A 0.1539 molal aqueous solution of cane sugar (mol. mass = 342 g mol^–1) has a freezing point of 271 K while the freezing point of pure water is 273.15 K. What will be the freezing point of an aqueous solution containing 5 g of gluocose (mol. mass = 180 g mol^–1) per 100 g of solution?

Some More Questions From Solutions Chapter

Calculate the osmotic pressure in pascals exerted by a solution prepared by dissolving 1.0 g of polymer of molar mass 185,000 in 450 mL at 37⁰C.

Suppose a solid solution is formed between two substances, one whose particles are very large and the other whose particles are very small. What kind of solid solution is this likely to be?

Amongst the following compunds identify which are insoluble, partially soluble and highly soluble in water?
(i) phenol (ii) toluene (iii) formic acid (iv) ethylene glycol (v) chloroform, (vi) pentanol.

Two liquids A and B boils at 145⁰C and 190⁰C respectively. Which of them has a higher vapour pressure at 80⁰C ?

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Solutions

A 0.1539 molal aqueous solution of cane sugar (mol. mass = 342 g mol–1) has a freezing point of 271 K while the freezing point of pure water is 273.15 K. What will be the freezing point of an aqueous solution containing 5 g of gluocose (mol. mass = 180 g mol–1) per 100 g of solution?

Some More Questions From Solutions Chapter

Calculate the osmotic pressure in pascals exerted by a solution prepared by dissolving 1.0 g of polymer of molar mass 185,000 in 450 mL at 370C.

Suppose a solid solution is formed between two substances, one whose particles are very large and the other whose particles are very small. What kind of solid solution is this likely to be?

Amongst the following compunds identify which are insoluble, partially soluble and highly soluble in water?(i) phenol (ii) toluene (iii) formic acid (iv) ethylene glycol (v) chloroform, (vi) pentanol.

Two liquids A and B boils at 1450C and 1900C respectively. Which of them has a higher vapour pressure at 800C ?

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation

A 0.1539 molal aqueous solution of cane sugar (mol. mass = 342 g mol^–1) has a freezing point of 271 K while the freezing point of pure water is 273.15 K. What will be the freezing point of an aqueous solution containing 5 g of gluocose (mol. mass = 180 g mol^–1) per 100 g of solution?

Calculate the osmotic pressure in pascals exerted by a solution prepared by dissolving 1.0 g of polymer of molar mass 185,000 in 450 mL at 37⁰C.

Amongst the following compunds identify which are insoluble, partially soluble and highly soluble in water?
(i) phenol (ii) toluene (iii) formic acid (iv) ethylene glycol (v) chloroform, (vi) pentanol.

Two liquids A and B boils at 145⁰C and 190⁰C respectively. Which of them has a higher vapour pressure at 80⁰C ?