Question

If you add a metal piece to excess acid, what of listed factors below will increase, decrease, or have no impact on how fast a reaction happens?

a) lower molarity (concentration) of a solution
b) higher molarity (concentration)of a solution
c) increase volume of a solution (with the same molarity)
d) decrease volume of a solution (with the same molarity)

Answer 1

Generally adding more (higher conc) acid will increase rate and lower M will decrease rate. Changing the volume up or down will not impact the rate assuming you have enough to begin with to have a reaction.

Answer 2

Ok, so the shape of the metal affects the reaction rate, correct? And any shape, will increase the rate, right?

Answer 3

I don't think the shape has much to do with reaction rate other than how much surface area is exposed. Increasing the surface area increases the rate of reaction.