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Class 10 Chemistry Chapter 17 Reaction Kinetics Test 6
Grade 10 Chemistry Chapter 17 Reaction Kinetics Test No.6
Prepare for your matric Chemistry examination with the Class 10 Chemistry Chapter 17: Reaction Kinetics Class Test 6, 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 improve their examination preparation. Students can use this Class 10 Chemistry Test 6 for practice, revision, and self-assessment according to the Punjab Board syllabus. Explore more Class 10 Chemistry model papers, chapter-wise tests, important questions, and exam preparation resources on 786Times.com to prepare confidently for the Punjab Board 2027 examinations.
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Chapter: 17
Total Time: 35 min
CHAPTER WISE CLASS TEST(Test # 6)
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.
Which of the following statements is correct?
(A) Collisions with energy equal to or greater than the activation energy lead to reaction.(B) Collision frequency is not related to the reaction rate(C) All collisions lead to a reaction.(D) Collisions with energy less than the activation energy lead to the reaction.
Answer: (A) Collisions with energy equal to or greater than the activation energy lead to reaction.
2.
Product formed when CaO reacts with water is:
(A) CaCO3(B) CaCl2(C) Ca(OH)2(D) CaSO4
Answer: (C) Ca(OH)2
3.
For many reactions, the rate doubles with every:
(A) 5°C rise(B) 10°C rise(C) 20°C rise(D) 50°C rise
Answer: (B) 10°C rise
4.
When a reaction proceeds ahead, how the concentrations of reactants and products change?
(A) Concentration of reactants increases and that of the products decreases.(B) Concentration of reactants decreases and that of the products increases.(C) Concentration of both reactants and products decreases.(D) Concentration of both reactants and products increases.
Answer: (B) Concentration of reactants decreases and that of the products increases.
5.
If pressure of chlorine gas is doubled, rate of reaction with hydrogen:
(A) Halves(B) Triples(C) Doubles(D) Stays same
Answer: (C) Doubles
6.
Active sites of enzymes are:
(A) General(B) Non-specific(C) Specific(D) Present everywhere
Answer: (C) Specific
7.
Enzymatic reactions during ripening convert starches into:
(A) Proteins(B) Fats(C) Sugars(D) Vitamins
Answer: (C) Sugars
8.
Lipid-soluble drugs diffuse more easily through cell membranes making them:
(A) More effective in shorter time(B) Less effective(C) Ineffective(D) Harmful
Answer: (A) More effective in shorter time
(PART – I)
Q.2 Write short answers to following questions.(6×2=12)
i.
Why is the rate of a reaction often very fast at the beginning of the reaction?
At the start the concentration of reactants is highest, so the number of collisions per second is greatest; as reactants are used up their concentration falls and the rate slows down.
ii.
Give a daily life example showing effect of temperature on rate of reaction.
Food spoils faster in hot weather than in a refrigerator; also, food cooks faster on a high flame and sugar dissolves faster in hot tea.
iii.
Give any two features of the catalytic action of an enzyme.
- Enzymes are highly specific: the active site fits only a particular substrate.
- They lower the activation energy and are not used up; they work best at an optimum temperature and pH.
iv.
How does pressure affect the rate of reaction for gases?
Increasing pressure squeezes gas molecules into a smaller volume (higher concentration), so collisions are more frequent and the rate increases; lowering pressure decreases the rate.
v.
From where do molecules get energy to attain higher energy state?
They gain energy from their surroundings, mainly by heating (absorbing heat) and through collisions with other fast-moving molecules; light can also supply energy.
vi.
How do rates of diffusion of medicines control their effectiveness?
A faster rate of diffusion lets the medicine cross cell membranes and reach the target quickly, so it acts sooner and more effectively; slow diffusion delays or reduces its action.
(PART – II)
Note: Attempt the following question.
Q.3: Write briefly about the role enzymes play in our body as biological catalysts.(5)
- Enzymes are protein molecules made by living cells that act as biological catalysts.
- They speed up body reactions (digestion, respiration, building of new cells) by lowering the activation energy.
- Each enzyme is specific: its active site fits only one substrate (lock-and-key model).
- They work at body temperature and an optimum pH, and are not used up in the reaction.
- Examples: amylase changes starch into sugar; pepsin digests proteins; enzymes also cause fruit ripening.
