Answer: Options (a) and (d) are the correct answer.
Explanation:
A catalyst is the substance which helps in increasing the rate of reaction.
Activation energy is the minimum amount of energy required by reactants to start the reaction. On addition of catalyst, the path of reaction changes because the energy barrier gap reduces and hence, the activation energy also decreases.
In the absence of catalyst, we need to increase the temperature so that reaction can occur quickly.
Whereas on addition of catalyst, there is no need to increase the temperature as the catalyst itself is sufficient to increase the rate of reaction. As a result, temperature should be lowered when there is addition of catalyst in the reaction.
Thus, we can conclude that catalysts can save money by essentially lowering the activation energy and temperature required.
The equation that shows the formation of chromium (ii) ion from neutral chromium atom is as follow
Cr ---> cr^2+ + 2e-
Cr^2+ is the chromium ion with oxidation state of two which is one of the common ion of chromium. Other common ion of chromium include chromium of oxidation state 6 and 3
Answer:
About 5 times faster.
Explanation:
Hello,
In this case, since the Arrhenius equation is considered for both the catalyzed reaction (1) and the uncatalized reaction (2), one determines the relationship between them as follows:

By replacing the corresponding values we obtain:

Such result means that the catalyzed reaction is about five times faster than the uncatalyzed reaction.
Best regards.