Organic Chem

anpanman SG

Hi!

May I know why is it that alcohol with more C atoms burn in air to give out more energy?

And how do you convert(eg. 1500 kJ/mol) into kJ/g ?

UltimaOnline SG

Hi!

May I know why is it that alcohol with more C atoms burn in air to give out more energy?

And how do you convert(eg. 1500 kJ/mol) into kJ/g ?

The energy given out during combustion is from the energy difference between the reactants and the products. CO2 and H2O are more stable than the compounds being combusted.

Convert number of moles to molar mass.

Eg. If 1 mole of the compound (eg. H2O2) has a mass of 34g, then 340kJ/mol = 340kJ/34g = 10kJ/g

yiha093 SG

The energy given out during combustion is from the energy difference between the reactants and the products. CO2 and H2O are more stable than the compounds being combusted.

so...? more stable so got more energy? ._.

SBS n SMRT SG

so...? more stable so got more energy? ._.

more stable mean more heat lost due to bond forming than heat gain in bond breaking, causing a greater enthalpy change (more negative), result in more exothermic r(x)s

yiha093 SG

i see. my cher never teach =<