Tag: surface chemistry
Questions Related to surface chemistry
The structural resemblence of substrate and inhibitor leads to______________ inhibition.
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non-competitive
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competitive
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both $A$ and $B$
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none of the above
Competitive Inhibitor - A competitive inhibitor is any compound which closely resembles the chemical structure and molecular geometry of the substrate.
Non-competitive Inhibitor - A non-competitive inhibitor is a substance that interacts with the enzyme, but usually not at the active site. The noncompetitive inhibitor reacts either remote from or very close to the active site.
The process which is catalysed by one of the product is called :
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acid - base catalysis
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autocatalysis
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negative catalysis
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homogeneous catalysis
A catalyst increases the rate of a reaction by:
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increasing the activation energy of the reaction
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increasing the value of rate constants $(k _f$ and $k _b)$
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increasing the enthalpy change of the reaction
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decreasing the enthalpy change of the reaction
A catalyst increases rate of reacting by decreasing activation energy. and increasing the enthalpy change of the reaction
The auto catalyst in the decomposition of arsine to Arsenic and $H _2$ is
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$As _2O _3$
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$As$
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$H _2$
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$Ge$
Which of the following is used as autocatalyst
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$ KMnO _4 $
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$ AI _2O _3 $
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$ CaC _3 $
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All of these
Which one of the following reactions is an example of auto-catalysis ?
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$2{ AsH } _{ 3 }(s)\rightarrow 2As(s)+3{ H } _{ 2 }(g)$
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${ N } _{ 2 }(g)\rightarrow 3{ H } _{ 2 }(g)\overset { Fe(g) }{ \rightarrow } 2N{ H } _{ 3 }(g)$
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${ 2SO } _{ 2 }(g)\rightarrow { O } _{ 2 }(g)\overset { NO(g) }{ \rightarrow } 2S{ O } _{ 3 }(g)$
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${ C } _{ 12 }{ H } _{ 22 }{ O } _{ H }(l)+{ H } _{ 2 }O(l)\overset { { H }^{ - }(l) }{ \rightarrow } { C } _{ 6 }{ H } _{ 12 }{ O } _{ 6 }(l){ HC } _{ 6 }{ H } _{ 12 }{ O } _{ 6 }(l)$
Auto-catalysis is defined as the reaction that is catalyzed by one of its product. in auto-catalysis product of reaction acts as a catalyst for the reaction. In auto-catalysis the initial rate of reaction rises as the catalytic product is formed instead of decreasing steadily.
In a reversible reaction, a catalyst:
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increases the rate of the forward reaction only.
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increases the rate of the forward reaction to a greater extent than that of the backward reaction.
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increases the rate of the forward reaction and decreases that of the backward reaction to a different extent.
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increases the rate of the forward and backward reactions equally.
In a reversible reaction, a catalyst increases the rate of the forward and backward reactions equally.
An increase in rate of reaction in forward direction by a catalyst for a reaction in equilibrium brings in an increase in concentration of products at faster rate and thus, rate of backward reaction also increases to same magnitude and the equilibrium position is not altered. In such reactions equilibrium constant does not alters.
Catalyst alters the state of equilibrium.
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True
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False
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Ambiguous
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Data insufficient
Option (B) is correct.
Catalyst does not alter the state of equilibrium. In the presence of a catalyst, both the forward and reverse reaction rates will speed up equally, thereby allowing the system to reach equilibrium faster. The addition of a catalyst has no effect on the final equilibrium position of the reaction.
The minimum energy level necessary to permit a reaction to occur is:
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internal energy
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threshold energy
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activation energy
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free energy
The minimum energy level necessary to permit a reaction to occur is called threshold energy.
Threshold energy is the energy level where some chemical/physical action happens. Threshold energy for production of a particle is the minimum kinetic energy a pair of traveling particles must have when they collide. The threshold energy is always greater than or equal to the rest energy of the desired particle.
Which of the following is/are not possible in case of auto-catalysis?
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Reactant catalysis.
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Heat produced in the reaction catalysis.
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Product catalysis.
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Solvent catalysis.