Ethanol, C2H5OH, is promoted as a clean fuel and is used as an additive in many gasoline mixtures. Calculate the ΔH°rxn for the combustion of ethanol. Substance ΔH°f(kJ/mol)
C2H5OH(l) –277.0
CO2(g) –393.5
H2O(g) –241.8

the answer is minerals.

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.