Question

Jenny and Mark complete a reactivity experiment by placing samples of metals into water. They initially place small shards of potassium into water and observe that hydrogen gas and potassium hydroxide solution are produced. To complete a second experiment, they place large cubes of potassium into water and observe the reaction again. Assuming the same amounts of potassium and water were used in each experiment, do you expect their observations about the products formed and reaction rate to be the same? Explain your answer.

Answer 1

Answer : Yes, their observations about the products formed would remain the same but the reaction rate will get altered with the change in size of the solid cubes of potassium into the water.

Explanation : The reaction of potassium with water is;


`2K + 2H_(2)O ----\ \textgreater \ 2KOH + H_(2)`

So here the products are not changing with the size of the potassium cube; but the rate changes because it gets more surface area for reaction with the increased size of reactant.