Which of the following is NOT a way to speed up a chemical reaction? (Select all that apply)
a
decreasing the temperature of one of the reactants
b
increasing the temperature of one of the reactants
c
decreasing the surface area of one of the reactants
d
increasing the concentration of one of the reactants
a
decreasing the temperature of one of the reactants
The option that is NOT a way to speed up a chemical reaction is:
c. decreasing the surface area of one of the reactants.
To determine which of the options is NOT a way to speed up a chemical reaction, let's analyze each option:
a. Decreasing the temperature of one of the reactants: This option is a valid way to slow down a chemical reaction. Lowering the temperature decreases the average kinetic energy of the molecules, resulting in fewer successful collisions between reactant molecules and a slower reaction rate. Hence, this option can accelerate a chemical reaction.
b. Increasing the temperature of one of the reactants: This option is a valid way to speed up a chemical reaction. Raising the temperature increases the average kinetic energy of the molecules, promoting more frequent and energetic collisions between reactant molecules. This higher energy leads to faster reaction rates.
c. Decreasing the surface area of one of the reactants: This option is also a valid way to accelerate a chemical reaction. Reducing the surface area of a reactant limits its contact with other reactant molecules, which decreases the number of effective collisions and slows down the reaction rate. Therefore, this option does not hinder the reaction's speed.
d. Increasing the concentration of one of the reactants: This option is a valid way to speed up a chemical reaction. Higher concentrations of reactants result in more reactant molecules being in close proximity, leading to a higher collision frequency. This amplifies the reaction rate, making it faster.
Based on the analysis above, the correct answer is option c: decreasing the surface area of one of the reactants. This is not a way to speed up a chemical reaction.