Aldehydes, Ketones and Carboxylic Acids — Chemistry STD 12 Science — Question

Explain the various uses of lanthanoids.

1. Define the following terms:

1. Ideal solution.
2. Azeotrope.
3. Osmotic pressure.

2. A solution of glucose (C₆H₁₂O₆) in water is labelled as 10% by weight. What would be the molality of solution?

(Molar mass of glucose = 180 g mol^-1).

CoSO₄Cl.5NH₃ exists in two isomeric forms ‘A’ and ‘B’. Isomer ‘A’ reacts with AgNO₃ to give white precipitate, but does not react with BaCl₂. Isomer ‘B’ gives white precipitate with BaCl₂ but does not react with AgNO₃. Answer the following questions.

1. Identify ‘A’ and ‘B’ and write their structural formulas.
2. Name the type of isomerism involved.
3. Give the IUPAC name of ‘A’ and ‘B’.

Answer the following questions:
Describe the preparation of potassium permanganate from pyrolusite ore. Write balanced chemical equation for one reaction to show the oxidizing nature of potassium permanganate.

Mention the type of compounds formed when small atoms like H, C and N get trapped inside the crystal lattice of transition metals. Also give physical and chemical characteristics of these compounds.

Derive formula for degree of dissociation and degree of condensation of the solute in the solvent.

Answer the following questions:

Account for the following:

1. Methylamine in water reacts with ferric chloride to precipitate hydrated ferric oxide.
2. Diazonium salts of aromatic amines are more stable than those of aliphatic amines.

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].

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.

1. How do you prepare:

1. K₂MnO₄ from MnO₂?
2. Na₂Cr₂O₇ form Na₂CrO₄?

2. Account for the following:

1. Mn²⁺ is more stable than Fe²⁺ towards oxidation to +3 state.
2. The enthalpy of atomization is lowest for Zn in 3d series of the transition elements.
3. Actinoid elements show wide range of oxidation states.