1.

What type of magnetism is shown by a substance if magnetic moments of domains are arranged in same direction?

On  adding  NaOH  to  ammonium  sulphate,  a  colourless  gas  with  pungent  odour  is evolved, which forms a blue-coloured complex with Cu²⁺ ion. Identify the gas.

Write the main reason for the stability of colloidal sols.

When a co-ordination compound CrCl₃.6H₂O is mixed with AgNO₃, 2 moles of AgCl are precipitated per mole of the compound. Write
(i)Structural formula of the complex.
(ii)IUPAC name of the complex.

From the given cells:
Lead storage cell, Mercury cell, Fuel cell and Dry cell Ans the following:
(i) Which cell is used in hearing aids?
(ii) Which cell was used in Apollo Space Programme?
(iii)Which cell is used in automobiles and inverters?
(iv)Which cell does not have long life?

When chromite ore FeCr₂O₄ is fused with NaOH in presence of air, a yellow-coloured compound (A) is obtained, which on acidification with dilute sulphuric acid gives a compound (B). Compound (B) on reaction with KCl forms an orange coloured crystalline compound (C).

(i)Write the formulae of the compounds (A), (B) and C.
(ii)Write one use of compound (C).
                                  
                                                OR

For a reaction :

(i)Write the order and molecularity of this reaction.
(ii)Write the unit of k.

The rate constant for the first-order decomposition of H2O2 is given by the following equation:

Calculate Ea for this reaction and rate constant k if its half-life period be 200 minutes. (Given: R = 8.314 JK^–1mol^–1).

(i) Differentiate between adsorbtion and absorption.

(ii)Out of MgCl2 and AlCl3, which one is more effective in causing coagulation of negatively charged sol and why?

(iii)Out of sulphur sol and proteins, which one form multimolecular colloids?

An element crystallizes in a f.c.c. lattice with cell edge of 250 pm. Calculate the density if 300 g of this element contain 2 × 10²⁴ atoms.