Chemistry - Class Twelve

Solutions

PREVIOUS    NEXT

Solution of NCERT In Text Question-2.5

Question - 2.5 - Calculate

(a) molality

(b) molarity and

(c) mole fraction of KI if the density of 20% (mass/mass) aqueous KI is 1.202 g mL –1.

Solution:

Given, 20% (mass/mass) aqueous solution of KI.

This means 20 gm of KI is dissolved in 80 gm of water.

Molar mass of KI = 39 + 127 = 166 g mol – 1

Mass of solute (W B) = 20 gm

Mass of solvent (WA ) = 80 gm

Molar mass of solute (M B)= 166 g mol – 1

Density of the aqueous KI = 1.202 g mL – 1

(a) Now, Molality of KI Solutions class 12 chemistry - NCERT In Text Solution21

Solutions class 12 chemistry - NCERT In Text Solution22

(b) Molarity of KI Solutions class 12 chemistry - NCERT In Text Solution23

Solutions class 12 chemistry - NCERT In Text Solution24

Thus, molarity of KI = 1.45 M

(c) Number of moles of KI Solutions class 12 chemistry - NCERT In Text Solution25 Solutions class 12 chemistry - NCERT In Text Solution26

Number of moles of H2O Solutions class 12 chemistry - NCERT In Text Solution27 Solutions class 12 chemistry - NCERT In Text Solution28

Now, Mole fraction of KI Solutions class 12 chemistry - NCERT In Text Solution29

Solutions class 12 chemistry - NCERT In Text Solution30

Thus, mole fraction of KI in the given solution = 0.265

PREVIOUS    NEXT

Topics covered in this chapter of Solutions

1. Solutions

2. Types of Solutions

3. Solutions - Concentration

4. Solution of NCERT In Text Questions

Class 12 Biology

  • Reproduction
  • ncert solution