How does an increace in reactant concentration affec the rate of reaction

  the reaction rate increases

Explanation:

An increase in reactant concentration generally provides more opportunities for reactants to get together and complete the reaction. The rate of reaction can generally be expected to increase.

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However, if the reactant whose concentration is being increased is not a rate-limiting reactant, the increased concentration may have no effect. The same will be true if the reaction rate is limited by a catalyst.