Question

Compare the quantities of reactants and the rates of experiments 1 and 5. in complete sentences describe the effect of the copper ion catalyst on the rate of the reaction.

Compare 5 and 6, describe the effect of the copper ion catalyst on the rate of the reaction.

experiment 0.00100M Na2S2O3 100% Starch 0,100M HCl 0,0100M KI Purified water 0.100 Cu2+ 0.400M KBrO2

1 1.5 1.5 3.0 3.0 6.0 0 3.0 172 seconds

5 1.5 1.5 3.0 3.0 4.5 1.5 3.0 119 seconds

6 1.5 1.5 3.0 3.0 3.0 3.0 3.0 115 seconds

Answer 1

The Reaction Rate for a given chemical reaction is the measure of the change in concentration of the reactants or the change in concentration of the products per unit time.

as we can see between 1 and 5 there is a huge difference at the time, T1 = 172 s and T5=119s, this means that the reaction rate increased. With a bit amount of 1.5Cu

and then between 5 and 6 we can observate there is a decrease in terms of time, but it is not that huge with 0.5M Cu

as a conclusion, we can observate that the first addition of Cu is the effective one, and the second produces no huge time differences.