REACTION KNETICS Flashcards
What happens to the rate of reaction as the reaction proceeds?
As the reaction proceeds the rate of reaction decreases.
What factors can be used to measure the rate of reaction? Also mention the instruments used.
The rate of reaction can be measured as follows:
1. Colour: Change in colour intensity. Measure using a spectrophotometer.
- Temperature: The change in temperature(only when endo or exo or energy input or output is given) using calorimeter.
- Pressure change: the pressure change is measured using a gas syringe. Only for gases and there should be a sealed container.
- Acidity Changes: the acidity changes is measured using the [H+], concentration of h plus ions of a acid in a solution.
- Mass change: mass change of a solid reactant only can be measured over time to determine the reaction rate.
What is the formula for deta h (enthalpy)?
Delta H= H products - H reactants
Tell two situations when the pressure of a gas of a reactant is not used to measure the rate of the reaction?
- When there is an open container or it is not mentioned if the container is open or closed.
- When the mole ratio of the gas is the same.
What is bond energy?
The energy required to break a bond
True or false?
Bond energy is not equal to the energy released when new bonds are formed.
True
How is a chemical bond formed?
A chemical bond is formed when the electrons hold the protons together. In addition the electrons repel each other as do the nuclei.
What is potential energy?
Potential energy is the energy of the electrons in a chemical bond and the number and type of molecules/ atoms.
What is kinetic energy?
Kinetic energy is the energy associated with the movement of the system.
What is enthalpy?
Enthalpy is the kinetic and potential energy in a system at constant pressure.
Why do an increase in surface area increases the reaction rate in a heterogenous mixture?
Increase in surface area increases the probability of the reactants to meet.
Define activation energy.
Activation energy is the minimum potential energy required for the reactants to form activation complex.
Tell the effects of adding a catalyst in both kinetic energy and potential energy .
In kinetic energy graph, adding a catalyst lowers the minimum energy requirement while in potential energy graph adding a catalyst lowers the activation energy.
Define activation energy.
Activation energy is the minimum potential energy required for the reactants to fuse and make the activation complex.
