A rise of about 10 degrees often doubles reaction rate because more molecules exceed activation energy.
Practise Kinetics & Equilibrium All Kinetics & Equilibrium topics
Raising the temperature increases the rate of most reactions, and a rise of about 10 degrees C often doubles or triples the rate for reactions with typical activation energies. Temperature increases both the collision frequency and the fraction of molecules with energy above the activation barrier, and the second effect dominates. The fraction of energetic molecules follows a Boltzmann distribution, so it grows exponentially with temperature. This is why cooling food slows spoilage and why reactions are often heated to proceed at a useful rate. The size of the effect depends on the activation energy, with larger barriers producing greater sensitivity.
Key ideas: The rule of thumb, rate doubles per 10 K, corresponds to Ea of roughly 50 kJ per mol at room temperature; precisely, the ratio k(T+10)/k(T) is about exp(Ea x 10 / (R T^2)). Reactions with larger Ea show a stronger effect, which is why some enzyme reactions increase by factors above 2 per 10 K until denaturation sets in.
Common mistakes and connections: Students claim that the rate rises because molecules move faster and collide more often; the main reason is more molecules above the energy barrier. Another mistake is applying the doubling rule to every reaction or to large ranges. Temperature changes k but not the order, whereas concentration changes the rate but not k. Compare Le Chatelier and van't Hoff for equilibrium.
Heating shifts the Maxwell-Boltzmann distribution so a larger fraction of molecules exceed Ea; this exponential growth is why rates often double per 10 degrees. The interactive lesson shows this as a live animation or chart.
Food spoils much faster in a warm kitchen than in a refrigerator because the rates of the spoilage reactions increase strongly with temperature.
A rise of about 10 degrees often doubles reaction rate because more molecules exceed activation energy.
Temperature Effect on Rate is a beginner topic in Kinetics & Equilibrium. It needs no earlier chemistry lessons and is a good starting point.
Study these earlier topics in Kinetics & Equilibrium first: Arrhenius Equation, Arrhenius Plot, Pre-exponential Factor.
The next topics in Kinetics & Equilibrium are Effect of Concentration on Rate and Effect of Surface Area.
Yes. The interactive lesson includes a self-check question on Temperature Effect on Rate, and the Kinetics & Equilibrium quiz draws on every topic in this area.
Temperature Effect on Rate is topic 28 of 91 in Kinetics & Equilibrium.