Question

Question: 58.5 gm of $NaCl$ and 180 gm of glucose were separately dissolved in 1000 ml of water. Identify the correct statement regarding the elevation of boiling point (b.p.) of the resulting solutions.
A. $NaCl$ solution will show higher elevation of b.p.
B. Glucose solution will show higher elevation of b.p.
C. Both the solutions will show equal elevation of b.p.
D. The b.p. eleven will shown by neither of the solutions

Answer 1

In this question, we will discuss and take some help from solutions chapter and choose the appropriate statement regarding elevation of boiling point. As evolution of boiling point is the phenomena in which boiling point of liquid is the temperature at which the vapour pressure of liquid becomes equal to the atmosphere pressure. So that, the boiling point is pure solvent. This increase in temperature is known as elevation in boiling point.

Complete step by step answer: As we know that, elevation of boiling point is equal to$\vartriangle {T_b} = i{K_b}m.$
As elevation of Boiling point depends upon the concentration of solute in a solution.
$\therefore \vartriangle {T_b} = i{K_b}m$
$\vartriangle Tb \propto i \times m$
For NaCl solution i=2.
As one molecule of NaCl dissociation to produce two ions.
Therefore. Molality of NaCl use How to find. So mobility is equal to the number of moles of solute per Kg. of solvent.
Thus, Molality of NaCl; m=$\dfrac{{58.5g}}{{58.5g/mol \times 1000ml \times \lg /m}} \times 1000gm$
For NaCl solution; =$i \times m$
thus $i = 2{\text{ }}and{\text{ }}m = 1$
=2x1
=2
For glucose solution,
I=1
As molecule of glucose do not dissociate
Therefore, molality of glucose;
$m = \dfrac{{180g}}{{180g/mol \times 1000ml \times 1g/mol}} \times 1000g$
M=1m.
Thus, NaCl solution will have higher elevation of boiling point ($\vartriangle {T_b}$) than glucose solution.
So, the correct answer is “Option A”.

Note: The Higher the osmotic pressure, the more hypertonic, the solution there are more particles in 1M NaCl than. In 1M glucose because of dissociation.
Therefore, NaCl is more hypertonic.
NaCl solution will show higher elevation of boiling point.