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Chemical Kinetics Lab

Investigate how temperature, concentration, and catalysts influence reaction rates. Adjust parameters to see the Arrhenius equation in action, observe particle collisions, and collect data for your own Arrhenius plot.

Guided Experiment: Effect of Temperature on Reaction Rate

If you increase the temperature of a reaction, what do you predict will happen to the rate constant k?

Write your hypothesis in the Lab Report panel, then click Next.

Low energy (slow)MediumHigh energy (fast)

Controls

Concentration [A]1.0 mol/L
Temperature300 K
Activation Energy (Ea)50 kJ/mol

Results

k=1.967e+1 s−1Eaeff=50 kJ/molk = 1.967e+1 \text{ s}^{-1} \quad E_a^{\text{eff}} = 50 \text{ kJ/mol}
Rate Constant k
1.967e+1 s-1
Reaction Rate
1.967e+1 mol/L/s
Half-life
3.523e-2 s
Fraction Over Barrier
1.967e-9
[A]
1.0 mol/L
T
300 K
Ea
50 kJ/mol

Arrhenius Plot: ln(k) vs 1/T

Data Table

(0 rows)
#Trial[A](mol/L)Temperature(K)k(s⁻¹)Rate(mol/L/s)Catalyst
0 / 500
0 / 500
0 / 500

Reference Guide

Arrhenius Equation

The Arrhenius equation describes how the rate constant depends on temperature.

k=A⋅e−Ea/(RT)k = A \cdot e^{-E_a / (RT)}

Where A is the pre-exponential factor (1010 s-1), Ea is activation energy, R is 8.314 J/(mol·K), and T is temperature in Kelvin. A plot of ln(k) vs 1/T gives a straight line with slope -Ea/R.

Activation Energy

Activation energy is the minimum energy molecules need to react. Only molecules with sufficient kinetic energy can overcome this barrier.

f=e−Ea/(RT)f = e^{-E_a / (RT)}

The fraction f of molecules with energy above Ea increases steeply with temperature. This is why a 10 K rise can roughly double the reaction rate.

Reaction Order

This simulator uses first-order kinetics: the rate depends linearly on concentration.

rate=k[A]t1/2=ln⁡2k\text{rate} = k[A] \qquad t_{1/2} = \frac{\ln 2}{k}

The rate constant k does not depend on concentration. Doubling [A] doubles the rate but leaves k unchanged. The half-life is constant regardless of initial concentration.

Catalysts

A catalyst speeds up a reaction by providing an alternative pathway with lower activation energy. It is not consumed in the reaction.

Eacat=Ea−ΔEacatE_a^{\text{cat}} = E_a - \Delta E_a^{\text{cat}}

On an Arrhenius plot, adding a catalyst shifts the line upward (higher intercept) while keeping the same slope shape but at a lower Ea. This increases k at every temperature.