Question

Would someone please check over this chemistry answer for me?
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?

Answer 1

I put for my answer..
I don't expect their observations to be the same because surface area effects reaction rate. The more surface area a reactant has the slower the reaction rate would be. The less surface area you have the faster the reaction rate would be. I would suspect a main difference in reaction rate between the shards and cubes. The cubes would produce the hydrogen gas and potassium hydroxide solution - but the reaction would take longer to occur then the shards due to the surface area.

Is this correct, how could it be a better answer?

Answer 2

Their observation of the production of hydrogen gas and potassium hydroxide will be the same for each experiment, but the rate of the reaction will be different. By using small shards of potassium during the first experiment, the surface area of the potassium is much greater, thus increasing the rate of reaction. By increasing the rate of reaction, the production of hydrogen gas and potassium hydroxide solution would be much faster (take less time).