SAMPLE PAPER – I (SOLVED)

CHEMISTRY - XI

Time: 3 hrs.

M. M.: 70

General Instructions:

1. All questions are compulsory.
2. Marks for each question are indicated against it.

Question number 1 to 8 are very short answer questions carrying one mark each. Answer these in one word or about one sentence.

1. Question number 9 to 18 are short answer questions carrying two marks each. Answer these in about 30 words.
2. Question number 19 to 27 are also short answer questions carrying three marks each. Answer them in about 40 words.
3. Question number 28 to 30 are long answer questions carrying Five marks each. Answer them in about 70 words.
4. Use log tables, if necessary. Use of calculator is not allowed.
5. The following set of quantum numbers is not possible. Explain, why? 1 <math>n = 2, l = 3, m = -3, m = +\frac{1}{2}</math>
6. Name a species which is isoelectronic with the following ion:

<math>N^{3-}</math>

For an isolated system <math>\Delta U = 0</math>, what will be <math>\Delta S</math>?

1. 4.

Explain the structure of CO, in terms of resonance.

1. What are the conditions under which gases deviate from ideality.
2. Justify that the following reaction is a redox reaction:

<math>H_2O(s) + F_2(g) \rightarrow HF(g) + HOF(g)</math>

1. Write the IUPAC name of following:

<math>CH_{,}=CH-C=CH</math>

1. What is the oxidation state of K in KO,.

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<math>1 \times 2 = 2</math>

1. Write balanced equation for reaction between:
2. Na₂O₂ and water
3. Ca metal with HCl

OR Describe the hybridisation in case of PCl_s. Why are the axial bonds longer as compared to equatorial bonds? 2

1. Use molecular orbital theory to explain why Be, molecule does not exist.
2. Explain the formation of σ and π bonds in C,H, with the help of diagram. Mention the hybrid state of two carbon atoms.

Calculate the mass of a photon with wavelength 3.6 Å. 2

<math>(h = 6.26 \times 10^{-34} \text{ JS})</math> Predict the products of electrolysis of an aqueous solution of AgNO. 2

with silver electrodes. Write reaction that occurs at each electrode. Write all the reactions involved in the preparation of sodium carbonate 2

from sodium chloride in Solvay Process. Complete the following equations: 2

1. Al + NaOH + H,O →
2. <math>H_3BO_3 \xrightarrow{\Lambda} A \xrightarrow{\Lambda} B</math>

A polluted water sample has been found to have 15 ppm CHCl, in it.

1. Express this value in percent by mass.
2. Determine the molality of chloroform in the water sample. 2

An alkene 'A' on ozonolysis gives a mixture of ethanal and 2

pentan-3-one. Write the structure and IUPAC name of A.

1. What is the basic principle involved in the following process:
2. Partition chromatography 1
3. Distillation under reduced pressure
4. (a) Explain why Be and Mg do not give colour to the flame whereas other alkaline earth metals do.
5. Why alkali and alkaline earth metals cannot be prepared by 1 chemical reduction methods?

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