## Meaning of subscript r

$\Delta G^{\circ}= \Delta H^{\circ} - T \Delta S^{\circ}$

$\Delta G^{\circ}= -RT\ln K$

$\Delta G^{\circ}= \sum \Delta G_{f}^{\circ}(products) - \sum \Delta G_{f}^{\circ}(reactants)$

Sierra Cheslick 2B
Posts: 61
Joined: Fri Sep 28, 2018 12:27 am

### Meaning of subscript r

What does the subscript "r" mean when used in relation to either deltaH or deltaS? This is used in the solutions manual for 9.67 in the 6th edition.

Katie Sy 1L
Posts: 57
Joined: Fri Sep 28, 2018 12:18 am

### Re: Meaning of subscript r

I'm not sure but I think it just means reaction

Sydney To 1D
Posts: 60
Joined: Fri Sep 28, 2018 12:15 am

### Re: Meaning of subscript r

The subscript r is an abbreviation of "reaction." Thus delta H "r" would imply the change in enthalpy of the reaction and delta S "r" would signify the entropy change of the reaction.

Albert Duong 4C
Posts: 66
Joined: Fri Sep 28, 2018 12:17 am
Been upvoted: 1 time

### Re: Meaning of subscript r

r signals that its for a reaction, but it doesn't really change anything so don't worry about it.