Chemistry Unit 10 Chemical Kinetics

Energy

Is the part of the universe that has the ability to do work and has the capacity to do work such as mechanical, electrical, chemical.

It may also affect matter like raises the tempreature adn eventually chaing the state.

Energy changes

all physical and chemical change involes in

Calorimeter

Used to measure heat energy change during a chemical/physical process

Temperature

Measure kinetic energy to measure the particles sample of matter

thermodynmics

Is the study of heat

Deals with transfer or energy during chemical and physical change

Enthalpy

Under conditon of constant pressure, the heat absorbed or realse is termed by

Reaction is Exothermic

if the heat is release, the temperature surounding is increase

Reaction is Endothermic

If the heat is absorbed, the temprature surounding is decrease

Exothermic

Transfer energy to the surrounding

Thernometer

Temperature increase can be detected using

Negative

If heat leaves (tansfer) exothermic

Positive

if the heat enters endothermic

Example of Exothermic Reactions

burning, neutralisation reactions between acids and alkalis, reaction between water and calcium oxide

Endothermic

Take in energy from the surrounding

Entropy

It is a mesure of disorder or random particles are arrangedEnergy mus

Endothermic Function

Energy must be added for reactions to occur

Disorder decrease

Increase in enthalphy

Exothermic Function

Reactions occurs spontaneously

Entropy increase,

Decrease in enthalphy

Reaction Rate

The rate of a chemical reaction is proportional to concentration of reactants present

Reaction Result

As reactants are used up during the process, the rate will decrease, and the reaction slows down.

Factors affecting the rates of chemical reactions

1. concentrations of reactants

2. the temperature

3. the presence of a catalyst

4. the surface no ddestroyed hen performin this function

Concentration of reactants

the higher the concentration of reactants, the faster the rate of the reaction.

The temperature

The higher the temperature, the faster the rate of the reaction

The presence of a catalyst

It increase rate without being used up (dont “cause” a reaction, they just speed it up)

The surface area of the reactants or catalyst

Reactions that involve solids often proceed faster if the solid is a fine powder because increasing the surface area.