Reaction Rate Chemistry Example 2

Follow the full solution, then compare it with the other examples linked below.

Example 2

medium
In a reaction, the concentration of a reactant decreases from 0.80โ€‰M0.80\,\text{M} to 0.20โ€‰M0.20\,\text{M} over 120120 seconds. Calculate the average rate of reaction.

Solution

  1. 1
    The average reaction rate is defined as the change in concentration over the time interval: rate=โˆฃฮ”[reactant]โˆฃฮ”t\text{rate} = \frac{|\Delta[\text{reactant}]|}{\Delta t}.
  2. 2
    Calculate the change in concentration: โˆฃ0.20โˆ’0.80โˆฃ=0.60โ€‰M|0.20 - 0.80| = 0.60\,\text{M} over ฮ”t=120โ€‰s\Delta t = 120\,\text{s}.
  3. 3
    Divide to find the rate: rate=0.60120=0.0050โ€‰M/s\text{rate} = \frac{0.60}{120} = 0.0050\,\text{M/s}

Answer

Rate=5.0ร—10โˆ’3โ€‰M/s\text{Rate} = 5.0 \times 10^{-3}\,\text{M/s}
The average rate of reaction measures how quickly reactant concentration changes over time. It is always expressed as a positive value.

About Reaction Rate

The speed at which reactants are converted into products in a chemical reaction, quantified as the change in concentration of a reactant or product per.

Learn more about Reaction Rate โ†’

More Reaction Rate Examples

Example 1 easy

List four factors that affect the rate of a chemical reaction and explain how each works.

Example 3 easy

Why does increasing temperature speed up a chemical reaction?

Example 4 medium

Two equal masses of calcium carbonate react with the same acid. One sample is powder and the other i

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