enthalpy changes and calorimetry

not including equations

define energetics:

energy changes during chemical reactions

what is an exothermic reaction? describe the diagram for an exothermic reaction

a reaction in which heat energy is given off

what is an endothermic reaction? describe the diagram for an endothermic reaction and state whether ΔH is +ve or -ve:

a reaction in which heat energy is taken in

what is enthalpy? what symbol is it represented by?

• a measure of the heat content of a substance

• represented by the symbol H

what are the units for enthalpy?

kJ mol^-1

what is enthalpy change? what symbol(s) is it represented by?

• heat energy change measured under conditions of constant pressure

• represented by ΔH

what are standard conditions for a reaction?

• 100 kPa

• stated temp (usually 298K)

what is the standard enthalpy change of formation of a compound? how is it represented?

enthalpy change which occurs when:

• 1 mole of the compound is formed from its elements

• under standard conditions and w/ everything in its standard state

• represented by ∆_f H ^Ɵ

what is the standard enthalpy change of combustion of a compound? how is it represented?

• the enthalpy change which occurs when ONE MOLE of the compound is BURNED COMPLETELY in oxygen under STANDARD CONDITIONS and w/ everything in its STANDARD STATE

• represented by ΔH^Ɵc

what is the specific heat capacity equation?

q = mcΔT

what is the equation for ΔH?

ΔH = q/moles

what is calorimetry?

the process of measuring the amount of heat energy released/absorbed during a chemical reaction