3a

Question 1

Exothermic

Answer 1

• Heat energy is given out
• If the energy to break bonds is less than the energy to form bonds
• (-ΔH)

Question 2

Endothermic

Answer 2

• Heat energy is taken in
• If the energy to break bonds is more than the energy to form bonds
• (+ΔH)

Question 3

Heat energy change

Answer 3

Heat energy(J) = mass(Kg) x specific heat capacity(J/kg°C) x change in temperature(ºC)
Q = mcΔT

Question 4

Change in enthalpy

Answer 4

Change in enthalpy(J/mol) = - heat energy(J) / moles(mol)
ΔH = -Q/n

Question 5

Enthalpy

Answer 5

Bond energy