Equations for enthalpy changes

• H_(products) - H_(reactants)

• Enthalpy change

• H_(reactants)- H_(products)

What are standard conditions?

tick the correct boxes

• 1 atm, 298K, 1moldm-3

• 101kPa, 25oC, 1moldm-3

• 101 atm, 25K, 1moldm-3

• 1kPa, 298oC, 1moldm-3

• CH4 + O2--> C+ H2O

• CH4(g) + O2(g)--> C(s)+ H2O(l)

• C(s) + O2(g) --> CO2(g)

• C + O2--> CO2

• CH4(s) + O2(g) --> CO2(g) + H2O(g)

• CH4(g) + O2(g)--> C(s)+ H2O(l)

• CH4(s) + 2O2(g) --> CO2(g) + 2H2O(g)

• CH4(g) + 2O2(g) --> CO2(g) + 2H2O(l)

• C + O2 --> CO2

• CH4(g) + O2(g)--> C(s)+ H2O(l)

• CH4 + O2--> C+ H2O

• C(s) + O2(g)--> CO2(g)

The enthalpy change which occurs when one mole of the compound is formed from its elements under standard conditions, and with everything in its standard state.

• Delta H c

• Delta H f

• Delta H r

2H2 + O2 --> 2H2O

2H2 + O2 --> 2H2O

Arrange the following compounds ascendingly according to their thermal stability.

Compound BaCl2(s) BaO(s) BaCO3(s) BaSO4(s)

Δ𝐻f∘(kJmol-1) −858.6 −548.1 −1213 −1473.2

• BaSO4>BaCO3>BaO>BaCl2

• BaO>BaCl2>BaCO3>BaSO4

• BaO>BaCO3>BaSO4>BaCl2

• 0

• 10

• 2

• 100