Combustion reactions

Question 1

Endo/exothermic?

Answer 1

EXOthermic

Question 2

Reactnts?

Answer 2

fuel, oxygen gas (and activation energy)

Question 3

Is it a type of oxidation reaction?

Answer 3

yes

Question 4

Define: oxidation reaction

Answer 4

oxygen and other reactant(s) combine to form oxides.

Question 5

Define: complete combustion

Answer 5

reaction occurring in an excess of oxygen gas (produces CO2 and H2O)

Question 6

Define: incomplete combustion

Answer 6

reaction occurring in an limited oxygen gas (produces CO and H2O)

Question 7

States of reactants in combustion reactions?

Answer 7

• Hydrocarbons (methane etc) should be gases due to weak dispersion forces
• Alcohols should be liquids, due to ability to form hydrogen bonds

Question 8

State of water in combustion reactions?

Answer 8

its state must reflect an enthalpy change from the fuel. If the fuel is s/g, water is (l). If the fuel is (l), then water is (g)

Question 9

if a question asks you to compare the energy released from a gaseous fuel to form water vapour, versus liquid water.

Answer 9

 Gas to gas: no change in state = no significant enthalpy change.
 Gas to liquid: energy released.
 Therefore, the gas to liquid reaction would cause more energy to be released overall.