Born-Haber's Five Way revenge

Chemistry Level pending

Riddler tells Batman that the person behinds these incidents is waiting for him at the Ace Chemical plant in the outskirts of Gotham city.

After reaching the chemical plant, Batman finds a mysterious figure with a red mask that covers his face.

The figure points to a large chemical vat that has a explosives placed all over it. the figures tells Batman "Lets put a smile on everyone's face"

Answer the question to help Batman stop the explosion

Calculate amount of free energy in the reaction HF ( aq ) gives $H^{+}$ ( aq ) and $F^{-}$ ( aq )

Details and Assumptions

(1) H( g ) gives an electron (e) and $H^{+}$ ( g ) ; Heat change = +315.3

(2) F( g ) and an electron (e) gives $F^{-}$ ( g ) ; Heat change = -83.0

(3) H( g ) and F( g ) give HF( g ) ; Heat change = -127.8

(4) HF( g ) gives HF( aq ) ; Heat change = -5.7

(5) $H^{+}$ ( g ) and $F^{-}$ ( g ) gives $H^{+}$ ( aq ) and $F^{-}$ ( aq ) ;

Heat change = -361.5

All values in kcal/mol

1.9 1.5 2.8 4.3

2 solutions

Vitthal Yellambalse
Aug 18, 2015

To calculate free energy in this reaction, we can use the thermo-chemical equations so that we obtain the heat changes for the reaction

HF( aq ) gives $H^{+}$ ( aq ) + $F^{-}$ ( aq )

To find the heat change,

Add the heat changes of equations (1), (2) and (5) and from their sum subtract the sum of heat changes of equations (3) and (4),

[(1) + (2) + (5)] - [(3) + (4)]

(315.3 - 83 - 361.5) - ( -127.8 -5.7)

= 4.3

Harshi Singh
Jan 24, 2016

SOMEWHAT TRICKY QUESTION YOU HAVE TO ARRANGE THE ENTHALPIES IN ORDER WITH SIGN CONSIDERATION......BUT EASY $\ddot\smile$