Coordination Compounds — Chemistry STD 12 Science — Question

Graphically explain the effect of temperature on the rate constant of reaction. How can this temperature effect on rate constant be represented quantitatively?

The elements of 3d transition series are given as:
Sc Ti V Cr Mn Fe Co Ni Cu Zn.
Answer the following:

1. Write the element which shows maximum number of oxidation states. Give reason.
2. Which element has the highest m.p?
3. Which element shows only + 3 oxidation state?
4. Which element is a strong oxidizing agent in + 3 oxidation state and why?

1. Define the following terms:

1. Co-enzymes.
2. Mutation in biomolecules.
3. Nucleotides.

2. List four main functions of carbohydrates in organisms.

When kept in water, raisin swells in size. Name and explain the phenomenon involved with the help of a diagram. Give three applications of the phenomenon.

For an elementary reaction:
2A + B → 3C
the rate of appearance of C at time ‘t’ is 1.3 × 10-⁴ mol L-¹ s-¹. Calculate at this time:

1. Rate of the reaction.
2. Rate of disappearance of A.

Discuss biological and industrial importance of osmosis.

Prove that the relative depression of vapour pressure is equal to the mole fraction of solute.

Match the items of Column I and Column II.

	Column I		Column II
i.	Lechlanche cell	a.	Cell reaction 2H2 + O2 ⎯→ 2H2O
ii.	Ni–Cd cell	b.	Does not involve any ion in solution and is used in hearing aids.
iii.	Fuel cell	c.	Rechargeable.
iv.	Mercury cell	d.	Reaction at anode, Zn ⎯→ Zn2+ + 2e-
		e.	Converts energy of combustion into electrical energy.

1. Define the following terms:

1. Mole fraction.
2. Ideal solution.

2. 15.0 g of an unknown molecular material is dissolved in 450 g of water. The resulting solution freezes at - 0.34°C. What is the molar mass of the material?

(K_f for water = 1.86 K kg mol^–1).