Energetics Flashcards
What does the amount of heat given out or taken in depend on?
the quantity of reactants.
What is enthalpy change?
Measuring heat change at a constant pressure.
What is temperature?
The average kinetic energy of the particles in a system
What is heat?
A measure of the total energy of all of the particles present in a given amount of substance.
What is the specific heat capacity?
The amount of energy needed to raise the temperature of 1g of substance by 1K.
How can you calculate enthalpy change?
Q=mc (delta)T
How is a flame calorimeter better than a simple calorimeter?
- the spiral chimney is made of copper,
- the flame is enclosed,
- the fuel burns in pure oxygen, rather than air.
When an acid is neutralised by an alkali what is the equation?
acid + alkali –> salt + water
What is a displacement reaction?
When a metal that is more reactive than another displaces the less reactive one to form a compound.
How can you find the temperature of a mixture immediately after mixing?
Draw a straight line through the graph points after mixing and then extrapolate back.
What is Hess’ Law?
The enthalpy change for a chemical reaction is the same, whatever the route taken from reactants to products.
Why are the enthalpy changes of formation so difficult to measure?
The reactants do not react directly to form the compound that you are interested in.
