Kerala Syllabus Class 10 Chemistry Model Question Paper Set 4

Practicing Chemistry Class 10 Kerala Syllabus Question Paper Set 4 English Medium helps identify strengths and weaknesses in a subject.

Chemistry Class 10 Kerala Syllabus Model Question Paper Set 4

Time: 1½ Hours
Score: 40 Marks

Instruction:

1. First fifteen minutes are cool off time. Read the questions carefully during this time:
2. Write the answers according to the instructions.
3. Consider the score while writing the answers.
4. Answer only one question for questions having choice.

Answer all the questions from 1 to 4. Each question carries l score. (1 × 4 = 4)

Question 1.
The Industrial preparation of Ammonia is known as …
a) Haber process
b) Contact process
c) Ostwald process
d) Bosch process
Answer:
a) Haber process

Question 2.
Statement 1: M shell contains a maximum of 18 electrons.
Statement 2: M shell has nine orbitals.
Which of the following options is true, regarding these statements?
A. Statements 1 and 2 are correct.
B. Statement 1 is correct, but 2 is not correct.
C. Statement 1 is not correct, but 2 is correct.
D. Statements 1 and 2 are not correct.
Answer:
A. Statements 1 and 2 are correct.

Question 3.
Match the following

Nature of Ore	Concentration method
(a) Ores are less dense than the impurities	(i) Levigation
(b) A solvent which dissolves the ore is used	(ii) Froth Floatation

A. (a) – ii, (b) – i, (c) – iii
B. (a) – i, (b) – ii, (c) – iii
C. (a) – iii, (b) – i, (c) – ii
D. (a) – ii, (b) – iii, (c) – i
Answer:
D. (a) – ii, (b) – iii, (c) – i

Question 4.
An alkane X with four carbon atoms undergo thermal cracking to get the products Y and Z (symbols are not real). Choose the correct option
A. X – C₄H₈, Y – CH₄, Z – CH₂ – CH₂
B. X – C₄H₁₀, Y – CH₄, Z – CH₂ = CH₂
C. X – C₄H₆, Y – CH₂ = CH₂ Z – CH₂ = CH₂
D. X – C₄H₁₀, Y – CH₃ – CH₃, Z – CH₂ = CH₂
Answer:
D. X – C₄H₁₀, Y – CH₃ – CH₃, Z – CH₂ = CH₂

Two questions from 5 to 11 have a choice. Each question carries 2 scores. (7 × 2 = 14)

Question 5.
a) In which test tube displacement reaction take place

b) Why doesn’t the displacement reaction take place in one of the test tubes?
Answer:
a) Test tube 1
b) In the second test tube, Ag is less reactive than copper. So, a displacement reaction cannot occur.

Question 6.
The flow chart of the industrial preparation of sulphuric acid is given. Complete it.

Answer:
a) SO_{2 (Sulphur Dioxide)
b) H2S2O7(Oleum)}

Question 7.
(A) Analyse the following.

a) Write the structural formula of X.
b) What is its IUPAC name?
Answer:
a) CH₃ – CH₂ – CH₂ – CH₂-OH
b) Butanol

OR
(B) One molecule of an aliphatic organic compound has 5 carbon atoms. It is identified as a saturated carboxylic acid.
a) Write the structural formula of this compound
b) Write the IUPAC name of a compound in this family with 4 carbon atoms.
Answer:
a) CH₃CH₂CH₂2CH₂COOH
b) Butanoic acid (CH₃CH₂CH_2COOH)

Question 8.
Choose the suitable method used in each of the following processes from the bracket.
[Liquation, Leaching, Froth floatation, Distillation]
a. Concentration of sulphide ores.
b. Refining of metals with low boiling points.
Answer:
a) Froth floatation
b) Distillation

Question 9.
Select from the box the correct gas law related to the given situations.
[Charles’s law, Boyle’s law, Avogadro’s law]
a) An inflated balloon kept in the sunlight bursts after some time.
b) The size of an air bubble rising from the bottom of an aquarium increases.
Answer:
a) Charles’s law
b) Boyle’s Law

Question 10.
The atomic number of an element is 11.
a) Write the sub-shell electronic configuration of this element.
b) What is the common oxidation state shown by this element?
Answer:
a) 1s₂2s₂2p₆3s₁
b) +l

Question 11.
(A) a) Name the polymer used to make switches.
b) Write the IUPAC name of this polymer 1 l.
Answer:
a) (Bakelite)
b) Phenol formaldehyde resin

B. Polyc’ lene tercphthalate (Polyester) is a very useful pnL tier.
a) What are the monomers of Polyethylene terephthalate (Polyester)?
b) Write any one use of this polyester?
Answer:
a) Ethylene glycol and Terephthalic acid
b) Manufacture of tarpaulin, bottles, fabrics, etc.

Two questions from 12 to 17 have a choice. Each question carries 3 scores. (6 × 3 = 18)

Question 12.
Graph of a reversible process, Img- 1 heat is given. Analyse the graph and answer the following questions.

a) Identify the part of the graph that represents the forward reaction [OA, BA, AC]
b) Identify the part of the graph that represents the equilibrium state
c) From the given statements, select the correct ones regarding chemical equilibrium.
i. Chemical equilibrium is static at the molecular level.
ii. Both reactants and products co-exist.
iii. The rates of forward and backward reactions are equal.
iv. Chemical equilibrium is attained in an open system.
Answer:
a) BA
b) AC
c) (ii) Both reactants and products co-exist.
(iii) The rates of forward and backward reactions are equal.

Question 13.
The figure given below represents the metals like
Fe, Cu, and Mg kept in dilute HCl

a) Which among these test tubes didn’t show any reaction? Which metal was kept in that test tube?
b) Which metal is present in test tube 1? Write the equation for the chemical reaction.
c) Arrange the given metals in the increasing order of their reactivity towards acids.
Answer:
a) 3rd test tube, Cu

b) Mg. Because Mg reacts vigorously with HC1 therefore more H₂ gas is produced.
Mg + 2HC1 → MgCl₂ + H₂

c) Mg > Fe > Cu

Question 14.
a) Complete the table.

Sulphide ore of zinc	Zinc blende (ZnS)
Carbonate ore of zinc	_____(i)_____
Sulphide ore of zinc	Zinc blende (ZnS)

b) Name the processes used in the conversion of zinc ore to zinc oxide after the concentration of the ore?
Answer:
a) (i) Calamine (ZnCO₃)
b) Roasting.
Zinc sulphide can be easily converted into its oxides by this method.

Question 15.
A) Compound (1) CH₃-CH₂ – CHO and Compound (2) CH₃-CH₂-CH₂-CHO are members of a homologous series.
a) Write the name of the family to which these compounds belong.
b) Write the IUPAC name of these compounds.
c) Write the structural formula of the functional isomer of compound (2)
Answer:
a) Aldehyde

b) (1) Propanal
(2) Butanal

c) CH₃-CO-CH₂-CH₃

OR
B) Pentan-2-one and pentan-3-one are a pair of isomers.
a) Write the structural formulae of these compounds.
b) To which family of organic compounds do they belong?
c) Write the structural formula of the functional isomer of these compounds
Answer:
a) CH₃-CO-CH₂-CH₂CH₃
CH₃CH₂COCH₂CH₃
b) Ketone
c) CH₃CH₂CH₂CH₂CHO

Question 16.
From the given statements, select and write down those related to gases:
a) The energy of the molecules is very high.
b) The force of attraction between the molecules is very high.
c) The distance between the molecules is very high.
d) The freedom of movement of the molecules is very low.
e) Since the collisions of the molecules are elastic in nature, there is no loss of energy.
f) As the molecules are so far apart, the volume of gaseous molecules is negligible in comparison with the total volume of the gas.
Answer:
a) The energy of the molecules is very high.
c) The distance between the molecules is very high.
e) Since the collisions of the molecules are elastic in nature, there is no loss of energy.
f) As the molecules are so far apart, the volume of gaseous molecules is negligible in comparison with the total volume of the gas.

Question 17.
A. (i) CH₄ + 2O₂ → _____ + 2H₂O + Heat
(ii)
a) Complete the chemical equation (i).
b) Name the reaction (ii).
c) Write any one use of Teflon?
Answer:
a) CH₄ + 2O₂ → CO₂ + 2H₂O + Heat
b) Polymerisation
c) Used to coat the inner surface of nonstick cookware.

OR
B. a) How is methanol prepared industrially?
b) Write the chemical equation of the reaction for the formation of methanol.
c) Write two uses of methanol.
Answer:
a) Methanol is produced industrially by combining carbon monoxide with hydrogen in the presence of catalysts.

b)

c) Methanol is used as a solvent in the manufacture of paint, for making varnish, and for making formalin.

Question 18 has a choice. It carries 4 scores.

Question 18.
A. Two statements regarding a shell are given below
• The last electron of this atom fills into the shell with principal quantum number n = 3
• This shell contains a total of 2 electrons.
a) Write the subshell electron configuration of this atom.
b) What is the total number of orbitals in the shell with n = 2?
c) Write the names of subshells present in the shell
d) How many orientations will be there for a subshell with l = 1
Answer:
a) ls²2s²2p⁶3s²
b) Total orbitals = n² = 2² = 4
c) The principal quantum number n = 2 can have angular momentum quantum numbers 1 from 0 to n-1.
For n = 2:
l = 0 (s-subshell)
l = 1 (p-subshell)

d) The total number of orientations is 2l + 1.
For the subshell with l = 1 (the p-subshell) m_l values are -1, 0, +1
Total number of orientations = 2l + 1
= (2× 1) + 1 = 3

OR
B. The last electron of an atom is added to the 3d subshell. There are 7 electrons in this subshell. Answer the following questions regarding this atom.
a) What is its atomic number?
b) Write its complete electron configuration.
c) To which block does it belong?
d) Find its period number and group number?
Answer:
a) 27
b) ls²2s²2p⁶3s²3p⁶3d⁷4s²
c) d block
d) Period – 4 and Group – 9