Octane is one of the commonest compounds found in petrol (gasoline). When it burns in a car engine this reaction takes place: C8H18(l) + 12.5O2(g) > 8CO2(g) + 9H2O(l) ∆H = –5400kJ mol–1 (a) Do the products contain more or less chemical energy than the reactants?

Melting and boiling are endothermic processes. this means that these processes absorb energy from their surroundings in order to occur. use this information and the data you collected in the phase change gizmo to describe what happens to the temperature of water when you boil it, then explain why this result occurs.

What is the solubility of substance?

Which of these is not an example of chemical weathering? a. iron-rich mineral rusting b. feldspar turning into clay c. limestone reacting with acid d. granite breaking up into sand