Subject

Chemistry

Class

CBSE Class 12

Pre Boards

Practice to excel and get familiar with the paper pattern and the type of questions. Check you answers with answer keys provided.

Sample Papers

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 Multiple Choice QuestionsShort Answer Type

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11.

Copper crystallises with face centred cubic unit cell. If the radius of a copper atom is 127.8 pm, calculate the density of the copper metal.

(Atomic mass of Cu = 63.55 u and Avogadro’s number NA = 6.02 x 1023 mol-1)


No. of atoms in unit cell, Z = 4

Radius = 127.8 pm

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12.

Iron has a body centred cubic unit cell with the cell dimension of 286.65 pm. The density of iron is 7.87 g cm-3. Use this information to calculate Avogadro’s number. (Atomic mass of Fe = 56.0 u)

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13.

The reaction N2(g) + O2(g)   2NO(g), contributes to air pollution whenever a fuel is burnt in air at a high temperature. At 1500 K, equilibrium constant K for it is 1.0 x 10-5. Suppose in a case [N2] = 0.80 mol L-1and [O2] = 0.20 mol L-1 before any reaction occurs. Calculate the equilibrium concentrations of the reactants and the product after the mixture has been heated to 1500 K.

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14.

The electrical resistance of a column of 0.05 M NaOH solution of diameter 1cm and length 50

cm is 5.55 x 103 ohm. Calculate its resistivity, conductivity and molar conductivity.

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15.

Write three distinct features of chemisorptions which are not found in physisorptions.

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16.

Explain each of the following observations:

(i) With the same d-orbital configuration (d4), Cr2+ is a reducing agent while Mn3+ is an oxidising agent.

(ii) Actinoids exhibit a much larger number of oxidation states than the lanthanoids.

(iii) There is hardly any increase in atomic size with increasing atomic number in a series of transition metals.

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17.

Name of the following coordination entities and describe their structure:

(i) [Fe (CN)6]4-

(ii) [Cr (NH3)4Cl2]+

(iii) [Ni (CN) 4]2-

(Atomic numbers Fe = 26. Cr = 24, Ni = 28
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18.

Write the IUPAC name of the following.

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19.

Write the IUPAC name of the following.

 

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20.

Write a reaction which shows that all the carbon atoms in glucose are linked in a straight chain.

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