Metals often form several cations with different charges. Cerium, for example, forms Ce3+ and Ce4+ ions, and thallium forms Tl+
and Tl3+ ions. Cerium and thallium ions react as follows: 2Ce4+(aq)+Tl+(aq)→2Ce3+(aq)+Tl3+(aq) This reaction is very slow and is thought to occur in a single elementary step. The reaction is catalyzed by the addition of Mn2+(aq) according to the following mechanism: Ce4+(aq)+Mn2+(aq)Ce4+(aq)+Mn3+(aq)Mn4+(aq)+Tl+(aq)→→ →Ce3+(aq)+Mn3+(aq)Ce3+(aq)+Mn4+(aq)Mn2+(aq)+Tl3+(aq) Part A What is the rate law for the uncatalyzed reaction?
Explanation: rate law shows the mathematical relationship by comparing the rate of reaction with the reactants concentration.
Rate law= k[reactantA][reactantB] .
Rate law can be used to derive an equation that shows a reactant as a function of time. Also, it can be use to calculate the rate of reaction from known concentration.
Since the reaction is thought to occur in a single reaction step for the uncatalysed reaction, and the reaction equation is: 2Ce4+(aq)+Tl+(aq)→2Ce3+(aq)+Tl3+(aq)
Rate of reaction= k [Ce^3+]^2 [Tl^3+]
Note that the rate of reaction = rate of appearance of products or rate of disappearance of reactants as shown above.
. A closed system allows only energy transfer but no transfer of mass. Example: a cup of coffee with a lid on it, or a simple water bottle. ... In reality, a perfectly isolated system does not exist, for instance hot water in a thermos flask cannot remain hot forever.
