4C7

Moderators: Chem_Mod, Chem_Admin

205154661_Dis2J
Posts: 109
Joined: Wed Sep 18, 2019 12:21 am

4C7

Postby 205154661_Dis2J » Sun Feb 09, 2020 11:37 pm

For 4C7, I know we calculated the enthalpy of vaporization for part b by turning 22.45g of ethanol into moles (which gives you 0.48), and then dividing 21.2kJ of energy by 0.48. This, in turn gives you 44.16 for the enthalpy of vaporization but I do not understand the question conceptually. Why are we dividing the energy by moles?

nicolely2F
Posts: 149
Joined: Sat Sep 14, 2019 12:17 am

Re: 4C7

Postby nicolely2F » Sun Feb 09, 2020 11:54 pm

The formula for enthalpy change is ΔH(vaporization) = q / n, which gives an answer of energy units per moles. This is because enthalpy of phase change measures the energy required to take 1 mole of some substance from one state to the other.


Return to “Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)”

Who is online

Users browsing this forum: No registered users and 2 guests