JAC Class 12 Chemistry Question Paper 2012 with Solution

About this paper

This is the Jharkhand Academic Council (JAC) Class 12 Chemistry paper from the 2012 board examination, with answers and worked steps under each question. It has four questions, each split into parts: Question 1 has eight multiple-choice items, Questions 2 and 3 have ten and nine short parts, and Question 4 has three longer parts, with 'Or' choices in two parts of Question 2. It covers solid state, electrochemistry, kinetics, surface chemistry, p- and d-block elements, coordination compounds, named organic reactions such as Kolbe, Reimer–Tiemann and Hoffmann bromamide, and biomolecules. Numerical work includes a first-order half-life, a zero-activation-energy rate constant and a copper-vessel E° problem. Marks and time are not printed.

Exam

JAC Class 12

Subject

Chemistry

Year

2012

Pages

4

Answers included

Yes

Paper pattern

• Question 1

  Eight multiple-choice parts, (i) to (viii)

• Question 2

  Ten short-answer parts, (i) to (x), two of them with an 'Or' choice

• Question 3

  Nine short-answer parts, (i) to (ix)

• Question 4

  Three longer parts, (i) to (iii), each with sub-questions

Topics covered

• Solid state
• Solutions and colligative properties
• Electrochemistry
• Chemical kinetics
• Surface chemistry
• Metallurgy of aluminium
• p-Block elements
• Lanthanoid contraction
• Coordination compounds
• Haloalkanes and haloarenes
• Alcohols, phenols and amines
• Polymers, biomolecules and detergents

Questions from this paper

1. A first-order reaction has a half-life of 34.65 seconds. What is its rate constant?
2. State the Hardy–Schulze rule.
3. Write the laboratory method of preparation of phosphine, with the equation.
4. Can we use a copper vessel to store 1 M AgNO₃ solution? Given E°(Ag⁺/Ag) = 0.80 V and E°(Cu²⁺/Cu) = +0.34 V, explain.
5. For a reaction the energy of activation is zero. If k = 1.6 × 10⁶ s⁻¹ at 280 K, what is the value of the rate constant at 300 K?
6. What is lanthanoid contraction? Give two examples of lanthanoid elements and state the oxidation states they exhibit.