Copper oxide reacts much faster with acid at 40°C than at 20°C. Why is this?

Question

Explain in terms of particles.

Luna Chen · Accepted Answer

It is due to a principle within chemical kinetics called collision theory

Collision theory states, that for particles to react, they have to collide in the correct orientation and have sufficient energy to create a successful (reacting) collision.

Take a simple Maxwell-Boltzmann distribution curve (this curve shows the number of particles in a system with a certain energy):

At the initial temperature ( #T1=20°C# ), only particles enclosed within the activation energy (Ea) and between T1 and the x-axis had sufficient energy to react. I.e. only particles within the dark green area could react.

Once the temperature was increased to #T2=40°C#, more particles had enough energy to react, as the number of particles with enough energy increased from the dark green area to the dark and light green area.

In simple terms: "As the temperature of a system is increased, more particles have sufficient energy to overcome the activation energy and perform a successful collision. Hence, more of the particles can readily react, increasing the rate of reaction at higher temperatures."

Avery Adams · Answer

undefined The reaction rate increases with temperature due to higher kinetic energy of particles, leading to more frequent and energetic collisions between copper oxide and acid molecules.

Mateo Aguilar · Answer

undefined The reaction rate of copper oxide with acid increases with temperature because higher temperatures provide more thermal energy to reactant particles, increasing the frequency and energy of collisions between copper oxide and acid molecules. This leads to more successful collisions and a faster reaction rate. Additionally, higher temperatures can disrupt the lattice structure of solid copper oxide, exposing more surface area for acid molecules to react with, further increasing the rate of reaction.