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Class 10 Chemistry Chapter 17 Reaction Kinetics Test 5
Grade 10 Chemistry Chapter 17 Reaction Kinetics
Prepare for your matric Chemistry examination with the Class 10 Chemistry Chapter 17 Reaction Kinetics Class Test 5, part of the Punjab Board 2027 Model Papers series. This chapter-wise Chemistry test is designed to help students revise important concepts, strengthen their understanding of Reaction Kinetics, and assess their exam preparation. Students can use this Class 10 Chemistry Test 5 for practice, revision, and self-assessment according to the Punjab Board syllabus. Practising chapter-wise model papers can help students improve their problem-solving skills and prepare more effectively for board examinations. Visit 786Times.com for more Punjab Board 2027 Model Papers, Class 10 Chemistry chapter tests, important questions, and examination preparation resources.
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Chapter: 17
Total Time: 35 min
CHAPTER WISE CLASS TEST(Test # 5)
Chemistry
Total Marks: 25
ABCD
1
2
3
ABCD
4
5
6
ABCD
7
8
NOTE:Four possible answers A, B, C and D to each question are given. The choice which you think is correct, fill that circle in front of that question with Marker or Pen ink. Cutting or filling two or more circles will result in zero mark in that question.
Q.1:(08)
1.
The number of collisions per unit volume of the reaction mixture is called:
(A) Collision energy(B) Activation energy(C) Collision frequency(D) Collision force
Answer: (C) Collision frequency
2.
Higher the concentration of reactants, more will be the number of:
(A) Products per second(B) Collisions between molecules(C) Catalysts(D) Inactive particles
Answer: (B) Collisions between molecules
3.
A change in mass may appear if a reactant or product is a:
(A) Solid(B) Liquid(C) Gas(D) Solution
Answer: (C) Gas
4.
If the reactants possess an energy higher than the activation energy, then the reaction will be:
(A) Slow(B) Fast(C) Not affected(D) Instantaneous
Answer: (B) Fast
5.
If a gas is absorbed in an open container, the apparent mass will:
(A) Increase(B) Remain same(C) Decrease(D) Become zero
Answer: (A) Increase
6.
If Mg and O2 react in a closed container, the total mass will:
(A) Increase(B) Decrease(C) Remain same(D) Double
Answer: (C) Remain same
7.
Which of the following explains the increase in rate of reaction in the presence of a catalyst?
(A) Catalyst provides extra energy to the reactant molecules(B) Catalyst provides an alternative pathway which lowers the activation energy.(C) Catalyst increases the collision frequency(D) Catalyst decreases the collision frequency
Answer: (B) Catalyst provides an alternative pathway which lowers the activation energy.
8.
In exothermic reactions, heat energy is:
(A) Absorbed(B) Released(C) No changes(D) Converted to light
Answer: (B) Released
(PART – I)
Q.2 Write short answers to following questions.(6×2=12)
i.
How does increase in the temperature increase the rate of a reaction?
Higher temperature gives particles more kinetic energy, so they move faster, collide more often, and more of them have energy ≥ activation energy; effective collisions and the rate increase.
ii.
Under what condition does a reaction take place?
A reaction takes place when reactant particles collide with energy equal to or greater than the activation energy and with the proper orientation (effective collision).
iii.
Why does the burning of sulphur proceed slower in air than in pure oxygen?
Air contains only about 21% oxygen, so the concentration of O2 molecules is lower and fewer collisions occur with sulphur; pure oxygen has a higher concentration, so the rate is faster.
iv.
Define activation energy
The minimum energy that the reactant particles must possess to start a chemical reaction (symbol Ea).
v.
Why a catalyst used in a reaction is preferably taken in the powdered form?
Powder has a larger surface area, so more reactant particles can contact the catalyst at the same time; this gives more active sites and a faster reaction.
vi.
What happens when Mg and O2 react in a closed container?
Magnesium burns to form white magnesium oxide: 2Mg + O2 → 2MgO. Since nothing can enter or escape, the total mass remains the same (law of conservation of mass).
(PART – II)
Note: Attempt the following question.
Q.3: How does chemical kinetics play an important role in the food industry?(5)
- It helps find the best temperature and conditions for food storage, slowing spoilage (e.g. refrigeration).
- Monitoring ethene production predicts ripening, so fruit is harvested and transported at the right time.
- It guides preservation methods such as freezing, drying and packaging.
- Enzymes are controlled in making bread, cheese and juices.
- Result: longer shelf life, less waste and better quality food.
