B.
Give reasons for the following statements.
1. Some reactions take place in the presence of a catalyst.
reaction
Answers
Answer:
Catalyst is a substance that increases the rate of a reaction without itself being consumed. Enzymes are naturally occurring catalysts responsible for many essential biochemical reactions.
The most important properties of catalysts are:
1. It alters the speed of a reaction, and it also affects the yield of the reaction product.
2. It actually takes part in the reaction even though it itself is not consumed or used up in the course of the reaction.
3. It provides an alternative pathway with a lower activation energy.
4. It is reaction-specific. It may not be effective in another reaction even if the two reactions are of similar type.
5. In a reversible reaction, a catalyst accelerates both the forward and the reverse reactions. So, the inclusion of a catalyst does not alter the equilibrium constant of a reversible reaction.
6. A catalyst can accelerate the rate of reaction but it can't initiate the reaction.
Answer:
In general, chemical reactions occur faster in the presence of a catalyst because the catalyst provides an alternative reaction pathway - or mechanism - with a lower activation energy than the non-catalyzed mechanism.
Explanation: