Question

Only two of these reactant concentration have a direct influence on the reaction rate Which two are they? In this experiment, you will determine the rate of an iodine clock reaction. The completion of this particular reaction is signalled by the sudden appearance of the dark-blue colour that is characteristic of the interaction of molecular iodine (I2) with starch. When the reaction is performed correctly, the blue colour appears so suddenly that it can be as startling as the sudden sound of an alarm clock, hence the title of the experiment. The rate of an iodine clock reaction depends on the concentrations of the reactants, as you would expect. Therefore, the time required for the appearance of the dark colour can be adjusted by adjusting the concentrations of the reactants (so one can set the “colour alarm” of a clock reaction just as you can set the sound alarm on a clock).You will study the rate of reduction of potassium persulfide (K2S2O8) by sodium iodide (NaI). The net ionic equation for this reaction is the following:S2O82– + 2 I - → 2 SO42– + I2 (1)The rate law for this reaction isRate = k [S2O82–]q [I -]

Answer 1

Matter and Change - Chemical reaction - Reactants and products.

A chemical reaction is a process in which some substances (reactants) change into different substances (products).

Answer:

The reactants are present in the start of the chemical reaction while products are present at the end of the chemical reaction.

A reaction rate is the change in concentration of a reactant or product with time, and it is affected by the concentration of the reactants and products. An increase in the concentration of one or more reactants results in an increase of the reaction rate.

In this case we have the following net ionic chemical reaction:

`S_2O_8^(-2)+2I^-\rightarrow2SO_4^(-2)+I_2`

We can see that the reactants are:

`\begin{gathered} S_2O_8^(-2) \\ \\ I^- \end{gathered}`

So an increase in the concentration of any of them would increase the rate of the reaction.

So the answer is B and C.

B: Iodide ions (I-)

C:Persulfate ions (S2O8-2)