SUB: CHEMISTRY
Max Marks: 80
Answers to this paper must be written n the paper provided separately.
You will not be allowed to write during first 15 minutes. This time is to be spent in reading the
question paper.
The time given at the head of this paper is the time allowed for writing the answers.
Section - I is compulsory. Attempt ANY FOUR questions from Section - II.
The intended marks for questions or parts of questions are given in brackets [ ].
SECTION - I [40 Marks]
[Attempt ALL questions from this Section]
Question 1
I.
Fill in the blanks with appropriate word/words:
[5x1=5]
a.
b.
c.
d.
e.
An element with 3 electron shells and 2 valence electrons belong to period ____________
and group __________.
When an atom or an ion loses an electron, it is said to be ____________.
Sodium acetate on hydrolysis forms sodium hydroxide and ____________.
The non-metallic component in stainless steel is ____________.
The conversion of ethanol to ethane is an example of ____________ reaction.
II.
Give one word answer for the following statements:
a.
b.
c.
d.
e.
A bond formed between two non-metallic elements by mutual sharing of electrons.
A base which is soluble in water.
A reaction in which the hydrogen of an alkane is replaced by another element like chlorine.
Name a non-metallic element which is a conductor.
Name a nitrate which on heating leaves no residue behind.
[5x1=5]
III. Choose the correct answer:
a.
b.
c.
[10x1=10]
The catalyst used in Ostwald’s process is:
i.
Fe
ii.
Pt
iii.
V2O5
iv.
PCl5
The chemical used in brown ring test is:
i.
CuSO4
ii.
FeSO4
iii.
ZnSO4
iv.
Fe2(SO4)3
Calcium
iv.
Phosphorus
Which of the following would yield a basic oxide?
i.
Sulphur
ii.
Silicon
iii.
d.
The electron affinity of the element in group 1 to 7:
i.
Increases and then decreases
iii. Increases
ii.
Decreases and then increases
iv. Decreases
e.
A compound having one lone pair of electrons:
i.
Water
iii.
ii.
Ammonia
iv.
Methane
Carbon tetrachloride
f.
With excess of chlorine NH3 forms:
i.
NH4Cl
ii.
NCl3
iii.
NOCl
g.
Which of the following statement is wrong about alkanes?
i.
They are all saturated hydrocarbons
ii.
They can undergo addition as well as substitution reactions
iii. They are almost non-polar in nature
iv. On complete combustion gives out CO2 and H2O
h.
Select the acid which contains 4 hydrogen atoms in it.
i.
Formic acid
ii.
Sulphuric acid iii. Nitric acid
iv.
N2
iv.
Acetic acid
i.
A black colour solid which on reaction with dilute sulphuric acid forms a blue coloured
solution is:
i.
Carbon
iii. Manganese (IV) oxide
ii.
Lead (II) oxide
iv. Copper (II) oxide
j.
The metal oxide that can react with acid as well as base is:
i.
Silver oxide
iii. Copper (II) oxide
ii.
Aluminium oxide
iv. Calcium oxide
IV.
Name the gas in each case:
a.
b.
c.
d.
e.
The gas produced by the action of concentrated sulphuric acid on sodium chloride.
The gas produced by the action of dilute nitric acid on copper.
The gas produced on heating sodium nitrate.
The gas that burns in oxygen with a green flame.
The gas that can be oxidized to sulphur.
V.
Write a fully balanced equation for each of the following cases:
a.
b.
c.
d.
e.
Red lead is warmed with concentrated HCl.
Magnesium metal is treated with dilute HCl.
Lead nitrate is heated in dry test tube.
Magnesium nitride is treated with warm water.
Acetic acid is warmed with ethanol in the presence of concentrated H2SO4.
VI.
Identify the substances P, Q, R, S and T in each case based on the
information given:
[5x1=5]
a.
The deliquescent salt P turns yellow on dissolving in water and gives a reddish brown
precipitate with sodium hydroxide solution.
The white crystalline solid Q is soluble in water. It liberates a pungent smelling gas when
heated with NaOH solution.
The pale green solid R turns reddish brown on heating. Its aqueous solution gives a white
precipitate with BaCl2 solution. The precipitate is insoluble in mineral acids.
The reddish brown liquid S is dissolved in water. When ethyne gas is passed through it, it
turns colourless.
The nitrate T does not leave any residue on heating.
b.
c.
d.
e.
[5x1=5]
[5x1=5]
VII. Answer the following:
a.
How would you distinguish between 𝑍𝑍𝑛𝑛2+ and Pb2+ using ammonium hydroxide solution?
[2]
b.
Copy and complete the following table which refers to the action of heat on some
carbonates.
[3]
Sl. No.
CARBONATE
1.
Zinc Carbonate
2.
Lead Carbonate
3.
Copper Carbonate
COLOUR OF THE RESIDUE ON COOLING
SECTION - II [40 Marks]
[Attempt ANY FOUR questions]
Question 2
a.
Draw the structure of a compound with three carbon atoms in the following cases: [3]
i.
An alkane with carbon to carbon single bond.
ii.
An alcohol containing three carbon atoms.
iii. An unsaturated hydrocarbon with a double bond between any two carbon atoms.
b.
Methane, Methene, Methanoic acid and Methanol. From the list name:
i.
A compound which is not possible.
ii.
A compound used to denaturing ethanol.
iii. A compound which is the first member of carboxylic acids.
[3]
c.
Write equations for the laboratory preparation of:
i.
Methane from sodium ethanoate.
ii.
Ethene from ethanol.
iii. Ethanol from monochloro ethane.
iv. Ethane from ethyl Iodide.
[4]
Question 3
a.
b.
c.
Calculate the percentage of water of crystallization in hydrated iron (II) sulphate
(Fe2SO4.7H2O) [Fe = 56, S = 32, O = 16, H = 1]
[3]
500 g of magnesium carbonate of 64% purity dissolves in excess of HCl as under: [3]
2HCl + MgCO3  MgCl2 + H2O + CO2
Calculate the weight of pure CO2 formed. [Mg = 24, C = 12, O = 16, H = 1, Cl = 35.5]
i.
What do you understand by the term empirical formula?
[1]
ii.
A gaseous hydrocarbon of vapour density 29 contains 82.76% of carbon. Calculate
its empirical formula and molecular formula. [C = 12, H = 1]
[3]
Question 4
a.
What is observed when:
i.
A small piece of iron is placed in copper sulphate solution.
ii.
Neutral litmus solution is added to sodium hydrogen carbonate solution.
iii. Copper turning are added to concentrated nitric acid.
iv. Lead nitrate solution is mixed with potassium iodide solution.
[4]
b.
Give the composition and uses of the following alloys:
i.
German silver
ii.
Bronze
[3]
c.
iii.
Alnico
The alumina is purified by Hall’s process. Write three fully balanced equations showing
how the alumina is purified. (Description of purification not required).
[3]
Question 5
a.
By giving one example in each case, state what do you understand from the terms:
[2]
i.
Strong acid
ii.
Weak acid
b.
Briefly describe, how you will prepare reasonably pure sample of copper sulphate crystals,
starting from copper carbonate? [Write the equations also]
[4]
c.
What do you understand by electroplating?
[2]
d.
A silver spoon is to be electroplated with gold. Name:
i.
The Cathode and
ii.
The anode used
[2]
Question 6
a.
An element X belongs to period 3 and group II of the periodic table. State:
i.
Its number of valence electrons
ii.
The valency of the element.
iii. Whether it is a metal or a non-metal
iv. The name of the element
b.
This question refers to the elements of the periodic table with atomic numbers from 3 to
18. Some of the elements are shown by letter, but the letters are not the usual symbols of
the elements.
[4]
3
A
11
I
4
B
12
J
5
C
13
K
6
D
14
L
7
E
15
M
8
F
16
N
9
G
17
O
[4]
10
H
18
P
Which of these are:
i.
Noble gases
ii.
Halogens
iii. Alkali metals
iv. Elements with valency 4
c.
Name two acids which can be prepared by using sulphuric acid.
[2]
Question 7
a.
i.
ii.
Name the raw materials used in the laboratory preparation of ammonia.
Name the chemical which dissolves gold.
b.
Match the atomic numbers 4, 14, 8, 15 & 19 with each of the following:
i.
A solid non-metal of valency 3
ii.
A gas of valency 2
iii. A metal of valency 1
iv. A non-metal of valency 4
[4]
c.
i.
ii.
[1]
[2]
What are amalgams?
Differentiate strong electrolyte and weak electrolyte. (Two points)
************
[2]
[1]