Rates of reactions

For a chemical [blank_start]reaction[blank_end] to take place, the particles must [blank_start]collide[blank_end] with enough energy and the right orientation to break the [blank_start]bonds[blank_end] holding them together. Then the [blank_start]particles[blank_end] can rearrange themselves into new compounds.

The rate of a reaction is the...

Which of these increase or decrease the rate of a reaction? (click as many as are needed - there are three factors listed in total)

Temperature is a measure of the [blank_start]heat[blank_end] energy that the particles have. The more heat energy particles have, the [blank_start]faster[blank_end] they move. This means that [blank_start]collisions[blank_end] are more likely to have enough energy to break the [blank_start]bonds[blank_end] in the reactants, so there will be more successful collisions per [blank_start]second[blank_end].

What is concentration?

[blank_start]Increasing[blank_end] the concentration increases the rate of the [blank_start]reaction[blank_end]. Because there are more [blank_start]particles[blank_end] in the same space, there will be more [blank_start]successful[blank_end] collisions just because they're crowded together more. Because there are more collisions, the [blank_start]rate[blank_end] of the reaction will be faster.

Which of these will react at the fastest rate?

Decreasing the particle size [blank_start]increases[blank_end] the rate of the reaction. [blank_start]Large[blank_end] chunks have a small surface area so react only slowly, because only those particles on the outside are available for [blank_start]collisions[blank_end]. Smaller pieces and powder have a [blank_start]larger[blank_end] surface area (for the same amount of reactant), and so more particles are available for collisions. Because more particles are available, there will be more [blank_start]successful[blank_end] collisions per second and therefore the rate of the [blank_start]reaction[blank_end] will increase.