Question

What expiriment is most likely to take the longest to change colour The Iodine Clock ReactionYou 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

Answer 1

Chemistry => Kinetics => Reaction Rate

The reaction rate tells us how fast the reactants are used up, or in other words, the speed with which products are produced.

The color change in this type of reaction is due to the formation of products. The rate at which they are produced depends on several factors, including the number of moles of products and reactants.

The longest will be the one with the fewest moles of reactants. The longest will be the one with the fewest moles of reactants and the greatest number of reactants.

We have as reactants the following compounds: NaI and K2S2O8.

Experiments 2 and 3 have a major mole of reactants. Experiment 2 has a greater number of moles of K2S2O8. Experiment 3 has a greater number of moles of NaI.

Experiment 1 has less number of moles of the reactants, which means that the reaction rate of this experiment will be lower and it will take the longest to change color.

Therefore, the answer will be: Experiment 1