Coordination Compounds — Chemistry STD 12 Science — Question

1. What is meant by:

1. Colligative properties.
2. Molality of a solution.

2. What concentration of nitrogen should be present in a glass of water at room temperature? Assume a temperature of 25°C, a total pressure of 1 atmosphere and mole fraction of nitrogen in air of 0.78. [K_H for nitrogen = 8.42 x 10^–7 M/mm Hg].

Answer the following question:
0.6mL of acetic acid (CH₃COOH), having density 1.06g mL^-1, is dissolved in 1 litre of water. The depression in freezing point observed for this strength of acid was 0.0205°C. Calculate the van’t Hoff factor and the dissociation constant of acid.

Explain Hoffmann bromamide degradation reaction with mechanism.

Explain the properties of vitamins and also classify them.

Assign reasons for the following:

1. The enthalpies of atomisation of transition elements are high.
2. The transition metals and many of their compounds act as good catalyst.
3. From element to element the actinoid contraction is greater than the lanthanoid contraction.
4. The E⁰ value for the Mn³⁺/Mn²⁺ couple is much more positive than that for Cr³⁺/Cr²⁺.
5. Scandium (Z = 21) does not exhibit variable oxidation states and yet it is regarded as a transition element.

Describe the structure of a fuel cell. Draw labelled diagram of a structure of fuel cell?

What happens to most probable kinetic energy and the energy of activation with increase in temperature?

A mixed oxide of iron and chromium, FeOCr₂O₃ is fused with sodium carbonate in the presence of air to form a yellow coloured compound (A). On acidification the compound (A) forms an orange coloured compound (B), which is a strong oxidising agent.

1. Identify the compounds (A) and (B).
2. Write balanced chemical equation for each step.

On the basis of crystal theory, octahedral in the presence of strong field ligand and weak field ligand. Explain the difference in crystal field splitting.