IIT JEE solutions Aakash

Please provide IIT JEE paper solutions given by Akash institute

[Arvind Kumar]

Here I am providing the solution for IIT JEE 2012 given by Akash institute:

Q. Choose the correct reason(s) for the stability of the lyophobic colloidal particles.
(A) Preferential adsorption of ions on their surface from the solution
(B) Preferential absorption of solvent on their surface from the solution
(C) Attraction between different particles having opposite charges on their surface
(D) Potential difference between the fixed layer and the diffused layer of opposite charges around the colloidal
particles

Answer (A, D)

Hints :
Lyophobic colloids carry either +ve or –ve charge. In order to acquire stability the colloidal particles attract
oppositely charged ions forming a diffused layer. A potential is developed between fixed layer and diffused layer
called zeta potential. Higher the value of zeta potential higher will be the stability of lyophobic colloid.

Q . For an ideal gas, consider only P-V work in going from an initial state X to the final state Z. The final state
Z can be reached by either of the two paths shown in the figure. Which of the following choice(s) is (are)
correct? [take ΔS as change in entropy and w as work done]

For more questions with their solutions I have uploaded the PDF file

Akash IIT JEE Solution Paper I

Akash IIT JEE Solution Paper II