Kerala Syllabus Class 10 Chemistry Model Question Paper Set 5

Practicing Chemistry Question Paper Class 10 Kerala Syllabus Set 5 English Medium helps identify strengths and weaknesses in a subject.

Chemistry Class 10 Kerala Syllabus Model Question Paper Set 5

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.

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

Question 1.
Which is the functional group present in butanol? (Hydroxyl, Alkoxy, Keto, Aldehyde)

a) P ∝ 1/V	i) Avogadro’s Law
b) V ∝ T	ii) Boyle’s Law
c) V ∝ n	iii) Charles’s Law

Answer:
Hydroxyl

Question 2.
Match the following
Choose the correct answer from the options given below.
A. (a)-ii,(b)-i,(c)-iii
B.(a)-i,(b)-ii,(c)-iii
C.(a)-ii,(b)-iii,(c)-i
D.(a)-ii,(b)-i,(c)-iii
Answer:
C.(a)-ii,(b)-iii,(c)-i

Question 3.
Statement 1: A Galvanic cell is an electrochemical cell that converts chemical energy into electrical energy.
Statement 2: A galvanic cell requires an external power source to function. Which of the following is correct regarding the above statements?
A. Both statements are correct
B. Both statements are not correct
C. Only statement 1 is correct
D. Only statement 2 is correct
Answer:
C. Only statement 1 is correct

Question 4.
In which one of the following reversible reactions, the change in pressure does not influence the equilibrium?

Answer:

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

Question 5.
Given below are two chemical equations.
CH₂ = CH₂ + H₂A
b) Img- 1
Answer:
a) CH₃ – CH₃
b) CH₃ – CH₂ – Cl

Question 6.
Write the structural formula of the given compounds
i) 2,3,5-Trimethylhexane
ii) Ethoxyethane
Answer:
i)

ii) CH₃ – CH₂ – O – CH₂ – CH₃ (C₄ H₁₀O)

Question 7.
Analyse the picture of an experiment.
a) What change took place on the surface of the iron nail?

b) Which among the following reactions are involved in the above change?
Fe²⁺ + 2e^– → Fe
Ag⁺ + le^– → Ag
Fe → Fe²⁺ + 2e^–
Ag → Ag⁺ + le^–
Answer:
a) Ag is deposited on the nail,
b) Fe → Fe²⁺ + 2e^–
Ag⁺ + le^– → Ag

Question 8.
A. a) Name a method of concentration of an ore in which impurities are heavier than the ore particles.
b) Select an ore that can be concentrated by using this method.
(Fe₃O₄, ZnCO₃, CaCO₃, ZnS)
Answer:
A) a) Froth floatation
b) ZnS

B. Concentrated Cu₂S is converted into oxide by roasting.
a) What method of concentration is suitable for these sulphide ores?
b) How are impurities like sulphur and phosphorus removed in this process?
Answer:
B) a) Froth floatation
b) Sulphur and phosphorous are removed as their oxides.

Question 9.

a) What is the total number of moles of reactants and products in the above reaction?
b) What is the effect of pressure in this reversible reaction? Explain.
Answer:
a) No. of moles of reactant = 2
No. of moles of product = 2 b) In a reversible reaction, if there is no change in the number of moles of reactants and products in the gaseous state, pressure will not affect the chemical equilibrium.

Question 10.
A) Convert the following temperature in Kelvin scale to Celsius scale
i) 500K
ii) 273K
Answer:
A. i) 500K
500 – 273 = 227°C

ii) 273K
273 – 273 = 0°C

OR
B) Atomic mass of some elements are given [Mg = 24,0= 16]
a) How many atoms are there in 120g Mg?
b) Find the mass of 4 × 6.022 × 10 ²³ oxygen atoms.
Answer:
a) Number of atoms
= \(\frac{\text { Given mass }}{\text { Gram atomic mass }}\) x Avogadro number
= \(\frac{120}{24}\) x N_A = 5 × 6.022 × 10²³

b) Mass of oxygen atoms
= \(\frac{Given number of particles}{Avogadro number}\) × Molar mass
= \(\frac{4 \times 6.022 \times 10^{23}}{6.022 \times 10^{23}}\) × 16g
= 64g

Question 11.
The Outermost Subshell electron configuration of two elements X and Y is given.
X = 3s² ; Y=3s² 3p⁵ (Symbols are not real)
a) What is the valency of the element X?
b) rite the chemical formula of the compound formed by the combination of X and Y?
Answer:
a) 2
b) XY₂

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

Question 12.
The positions of two elements A and B in the periodic table are given. (Symbols are not real)
A – 4^th period and 2nd group
B – 2^nd period and 16^th group
a) Write the subshell electron configuration of A and B?
b) Write the value of n and/electrons in the outermost subshell of A?
c) What type of chemical bond is present in this compound AB?
Answer:
a) A – ls²2s²2p⁶3s²3p⁶4s²
B – 1s² 2s² 2p⁴
b) n = 4, l = 0
c) Ionic bond

Question 13.
A. Structural formulas of two organic compounds are given.
i) CH₃ – O – CH₂ – CH₃
(ii) CH₃ – CH₂ – CH₂ – OH
a) Write the IUPAC name of each compound.
b) Write one similarity between these compounds.
c) What is this phenomenon known as?
Answer:
i) Methoxyethane
ii) Propan-l-ol
b) The two compounds have the same molecular formula (C₃H₈O)
c) Functional group isomerism

Or
B. A saturated hydrocarbon has 5 carbon atoms in the main chain. A methyl radical is present on the second carbon atom.
a) Write the structural formula of the compound.
b) What is the IUPAC name of the compound?
c) Write the structural formula of a chain isomer of this compound.
Answer:

Question 14.
a) Which of the following chemicals are used to prepare ammonia (NH₃) in the laboratory? [NaCl, Ca (OH)₂, CaCl₂, NH₄Cl]
b) Ammonia gas produced is passed through quick lime. Give a reason.
c) Which product is obtained when ammonia reacts with HCl?
Answer:
a) NH₄CI and Ca(OH)₂
b) To remove moisture content. Quick lime is used as a drying agent.
c) NH₃+HC1 → NH₄Cl

Question 15.
Observe the figure in which a copper plate is immersed in AgNO₃ (Silver Nitrate) solution. (Reactivity: Cu > Ag)

a) The reaction taking place here is a redox reaction. Why?
b) What change can be observed on the copper plate?
c) Write the equation of the oxidation reaction taking place here.
Answer:
a) Oxidation and reduction take place simultaneously, so this reaction is a redox reaction.
b) A layer of Ag is deposited on the Copper plate, and the silver nitrate solution turns blue.
c) Cu → Cu²⁺ + 2e^–

Question 16.
A. Complete the table using the names of reactions given in the box.
Polymerisation, Combustion, Addition reaction, Substitution reaction, Thermal cracking
a) Addition reaction
b) Substitution reaction
c) Combustion

Chemical equation	Name of reaction
CH3-CH=CH2 + H2 → CH3-CH2-CH3	(a)
CH3-CH3 + Cl2 → CH3-CH2-Cl+HCl	(b)
CH4 + 2O2 → CO2 + 2H2O	(c)

Answer:
a) Addition reaction
b) Substitution reaction
c) Combustion

OR
B. Match the columns A, B and C suitably.

A Reactants	B Products	c Name of Reaction
CH4 + Cl2	CO2 + 2H2O	Addition
CH4 + 2O2	CH2 = CH2	Thermal Cracking
CH3 – CH2 – CH3	CH3Cl + HCl	Combustion
CH = CH + H2	CH2 = CH2 + CH4	Substitution

Answer:

A Reactants	B Products	c Name of Reaction
CH4 + C12	CH3Cl + HCl	Substitution reaction
CH4 + 2O2	CO2 + 2H2O	Combustion
CH3 – CH2 – CH3	CH2 = CH2 + CH4	Thermal Cracking
CH = CH + H2	CH2 = CH2	Addition

Question 17.
Some metals and” their refining methods are given. Find the appropriate pair.

Metal	Refining Method
Tin	Distillation
Copper	Liquation
Zinc	Electrolytic Refining

Answer:

Metal	Refining Method
Tin	Liquation
Copper	Electrolytic Refining
Zinc	Distillation

Question 18 has a choice. It carries 4 scores.

Question 18
A. Some materials are given below:

a) From the given materials, choose the appropriate ones to construct a galvanic cell and draw the diagram of the cell. (Order of reactivity: Mg > Fe > Cu > Ag)
b) Which is the anode of this cell?
c) At which electrode does reduction take place?
d) Write the chemical equation of the reaction taking place at the cathode.
Answer:
a) Mg, MgSO₄, Cu, CuSO₄, Salt bridge, connecting wire with voltmeter connected.

b) Mg/Magnesium
c) Cathode (Cu rod)
d) Cu²⁺ + 2e^– → Cu

OR
B. Observe the pictures given below. Based on the reactivity series, predict which of these undergoes a displacement reaction. Complete the table.

Metal	Solution	Displacement
Mg	CuSO4	reaction
Ag	CuSO4	(a)
Mg	ZnSO4	(b)
Mg	AgNO3	Takes place

Answer:
a) Takes place
b) Does not take place
c) Takes place
d) Does not take place