Question 61 : The chemical reactions in which reactants require high amount of activation energy Are generally?
1. Fast
2. Slow
3. Spontaneous
4. Instantaneous
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Question 62 : The rate of a reaction increases with the increase of concentration of reactants because?
1. None of these
2. Number of molecules per unit volume increases
3. Number of collisions per unit time between the reacting molecules increase due to increase of No. of molecules of reactants
4. The enthalpy change for the reaction decreases.
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Question 63 : Among the following reactions, the fastest one?
1. Precipitation of AgCl by mixing AgNO₃ and NaCI solutions
2. Conversion of monoclinic sulphur to rhombic sulphur
3. Rusting of iron
4. Burning of coal
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Question 64 : When one of products is removed from the reaction, the direction of reverse reaction is
1. Forward
2. both (a) and (b)
3. None
4. Backward
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Question 65 : In case of Slow reaction, if the temperature is increased by 10 K, then point out the false statement?
1. Energy of activation decreases
2. Average K.E decreases
3. Threshold energy. increases
4. Number of collisions ,get multiplied
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Question 66 : Reaction between H₂ and CL₂ occurs in the presence of sunlight. Its rate is independent of concentration of H₂ and Cl₂ so it is order reaction,
1. zero
2. First
3. Second
4. Third
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Question 67 : Molecular reactions have usually?
1. Fast Speed
2. Moderate speed
3. Slow speed
4. None of these
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Question 68 : In the reaction: 2N0 + O₂ → 2NO₂ if the concentration of NO is halved, the rate will decrease by
1. none of these
2. 2 Times
3. 3 Time
4. 1/2 times
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Question 69 : In a chemical reaction, only those collisions of molecules are effective in which the colliding molecules possess a minimum amount Of energy called?
1. Average internal energy
2. Activation energy
3. Threshold energy.
4. None of these
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Question 70 : When one of the products of reaction acts, as catalysts then 'such a process is called?
1. Positive catalysts
2. Bio-Catalysts
3. None of these
4. Auto catalysts
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