EASY
Earn 100

When ammonium chloride is mixed with barium hydroxide in a beaker, it becomes cold.

Important Questions on Energy

HARD
Chemistry>Change>Energy>Energy Changes in Chemical Reactions
If the first order rate constants for the decomposition of ethyl iodide at 600 K and 700 K are 2.0×10-5 s-1 and 2.0×10-4 s-1 respectively, the activation energy for this reaction in kJmol-1 is
EASY
Chemistry>Change>Energy>Energy Changes in Chemical Reactions
The unit of activation energy is
EASY
Chemistry>Change>Energy>Energy Changes in Chemical Reactions
An exothermic reaction X→Y has an activation energy 30 kJ mol-1. If energy change ΔE during the reaction is -20 kJ, then the activation energy for the reverse reaction in kJ is                (Integer answer)
HARD
Chemistry>Change>Energy>Energy Changes in Chemical Reactions
For the following reactions
A→700KProduct
A→catalyst500KProduct
It was found that the Ea is decreased by 30 KJ/mol in the presence of catalyst. If the rate remains unchanged, the activation energy for catalysed reaction is (Assume pre-exponential factor is same)
EASY
Chemistry>Change>Energy>Energy Changes in Chemical Reactions
A negative catalyst _____ the activation energy.
EASY
Chemistry>Change>Energy>Energy Changes in Chemical Reactions

Consider the following energy profile

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Which of the following reactant is most suited for the above energy profile?

HARD
Chemistry>Change>Energy>Energy Changes in Chemical Reactions
If a reaction A + B → C  is exothermic to the extent of 30 kJ/mol and the forward reaction has an activation energy 70 kJ/mol, the activation energy for the reverse reaction is
MEDIUM
Chemistry>Change>Energy>Energy Changes in Chemical Reactions
The rate constant  k ′ of one of the reaction is found to be double that of the rate constant k ″ of another reaction. Then the relationship between the corresponding activation energies of the two reactions E a ′ and E a ″ can be represented as:
MEDIUM
Chemistry>Change>Energy>Energy Changes in Chemical Reactions
Natural resources should be used _____ (rationally/ carelessly/ lavishly/ illogically).
EASY
Chemistry>Change>Energy>Energy Changes in Chemical Reactions
During endothermic reaction, energy is _____.
EASY
Chemistry>Change>Energy>Energy Changes in Chemical Reactions
The heat contents of products is more than that of the reactants in an _____ reaction.
EASY
Chemistry>Change>Energy>Energy Changes in Chemical Reactions
The rate constant k ′ of one reaction is double the rate constant k ″ of another reaction. Then the relationship between the corresponding activation energies of the two reactions E a ′  and  E a ′′ will be -
(Assume the pre-exponential factor & temperature to be same)
EASY
Chemistry>Change>Energy>Energy Changes in Chemical Reactions
Threshold energy minus the energy which the molecules actually possess is called _____.
MEDIUM
Chemistry>Change>Energy>Energy Changes in Chemical Reactions
For a reaction for which the activation energies of the forward and reverse directions are equal in value :
EASY
Chemistry>Change>Energy>Energy Changes in Chemical Reactions
In exothermic reaction, _____ of heat occurs.
MEDIUM
Chemistry>Change>Energy>Energy Changes in Chemical Reactions
Which of the following statements about the construction of a dam are incorrect?
EASY
Chemistry>Change>Energy>Energy Changes in Chemical Reactions

During exothermic reaction, energy is _____.

HARD
Chemistry>Change>Energy>Energy Changes in Chemical Reactions
Aluminium is used in the alumino-thermic process because:
HARD
Chemistry>Change>Energy>Energy Changes in Chemical Reactions
Find out % of reactant molecules crossing over the energy barrier of 325 K given that ΔH325=0.12 KCal & Eab/w=0.02 KCal
EASY
Chemistry>Change>Energy>Energy Changes in Chemical Reactions
Endothermic reactions are more feasible at _____ temperature.