What effect does a catalyst have on a reaction? O A. A catalyst increases the concentrations of products.
B. A catalyst contributes energy to a reaction,
C. A catalyst speeds up the rate of a reaction.
D. A catalyst makes it possible for a reaction to happen.

a 20-cm-long, cylindrical graphite (pure carbon) rod is inserted into an oxidizing atmosphere at 1145 k and 1.013 x 105 pa pressure. the oxidizing process is limited by the diffu- sion of oxygen counterflow to the carbon monoxide that is formed on the cylindrical surface.