Which got me thinking...Surely something wrong there?
Kerosene a.k.a. paraffin, is a mixture of hydrocarbons. Although it is not a pure single substance, we could, for the purposes of argument, consider an average formula to be something in the region of C12H26 (see e.g. https://en.wikipedia.org/wiki/Kerosene ).
The burning of kerosene consumes oxygen (O2) and results in the production of carbon dioxide (CO2) and water (H2O), according to an equation that would be something like:
C12H26 + 18.5O2 = 12CO2 + 13H2O
What this tells us is that burning 1mol of kerosene produces 13mols of H2O, plus 12mols of CO2. (1 mol of a substance is contained in the molecular weight of that substance in grams)
The molecular weights are as follows:
Kerosene average MW = 170 (so 170g of kerosene would contain 1mol of the substance)
Water MW = 18
CO2 MW = 44
The density of kerosene is around 0.8g/ml, so 1 litre of kerosene = 800g, which equates to 800 / 170 = 4.706mols
The amount of water produced by burning 1 litre of kerosene will be 4.706 x 13 = 61.2 mols of water, which weighs 61.2 x 18 = 1102g i.e. 1.1 litres of liquid water but, since this will be water vapour (i.e. a gas) it will be around 1475 litres of water vapour at 20degC (since 1 mol of a gas occupies 24.1 litres at normal temp and pressure; see https://www.engineeringtoolbox.com/stp-standard-ntp-normal-air-d_772.html). i.e. burning 1 litre of kerosene will release around 1475 litres of water vapour at room temp.
Burning that 1litre of kerosene will also produce 4.706 x 12 = 56.47mols of CO2, which is 2.485kg of CO2, which is around 1360litres of CO2 gas at 20degC.
Anyway, long story short, burning 1 litre of kerosene will produce around 1.1 litres of liquid water.