chemistry kinetics

Question 1

what is reaction rate?

Answer 1

Reaction rate is defined as the change in concentration (or amount) of a reactant or product over time.

Question 2

What is the formula for finding the rate of a chemical reaction?

Answer 2

rate of reaction= Amount of reactant used up or products formed/ time

Question 3

What are the three methods for measuring the rate of reaction.

Answer 3

1. Measuring a decrease in mass
   - For reactions that produce gases, you can measure the rate by observing the decrease in mass over time.
   - As gas is released, the mass decreases. This method is straightforward but should be conducted in fume cupboard for safety.
2. ** Measuring the volume of mass given of gas given off**
   - use a gas syringe to measure the gas volume produced over time.
   - This method is accurate for reactions that generate gases.
3. ** Timing how long a precipitate takes to form.**
   - This approach is suitable when the product of the reaction is a precipitate.
   - Measure how long it takes for a mark to become obscured by the precipitate.
   - For consistent comparison of reaction rates, always use the same observer and reference mark

Question 4

how do you work out the gradient on a graph?

Answer 4

Gradient = change in y/ change in x

Question 5

what are the features of the Maxwell-Boltzmann distribution graph?

Answer 5

1. The curve originates at the origin, indicating that no molecules have zero kinetic energy.
2. it rises sharply to a peak that represents the most common kinetic energy level among the molecules. before gradually decreasing.
3. the total area under the curve is equivalent to the total number of molecules.
4. the peak of the curve shows the most probable kinetic energy a single molecule can have.
5. on average, the kinetic energy of all molecules is a bit higher than the peak energy.

Question 6

What happens to the Maxwell-Boltzmann graph when the temperature increases?

Answer 6

• As the temperature rises, a greater number of molecules attain the kinetic energy necessary to surpass the activation energy, leading to a reaction.
• Consequently, the distribution curve shifts to the right, indicating that more molecules have acquired sufficient kinetic energy.
• Despite the total number of molecules remaining constant, the area under both curves is unchanged, which results in a lower peak height. This is because the distribution of kinetic energies broadens at higher temperatures.