An element with density 10g/cc forms a cubic cell with edge length of 3 x 10^-8 cm. What is the nature of cubic unit cell if the atomic mass of the element is 81g/mol ?

Name the reagents used in following reactions :

(i)

(ii) CH₃-COOH ClCH₂COOH

Calculate the amount of CaCl₂ (molar mass = 111g/mol) which must be added to 500g of water to lower its freezing point by 2K assuming CaCl₂ is completely disassociated. (K_f for water is = 1.86 Kg K/mol)

Calculate emf of following cell at 298 K

Sn|Sn²⁺(0.001M)||H⁺(0.01M)||H₂(g)(1bar)|Pt (s)

E°_(Sn2+/Sn) = -0.14V

E ° (H+/H₂) = 0.00V

Give reason for following observation:

(i) Physisorption decrease with increase in temperature.

(ii) Addition of alum purifies the water.

(iii) Brownian movement provides stability to colloidal solution.