[paukwa]

hey i am having trouble with this question i get a different answer than the book says.

1) A 10.0G sample of liquid gallium metal, at its melting point, is added to 50.0g of water in a polystyrene calorimeter. The temperature of the water changes from 24.0C to 27.8C as the gallium solidifies. Calculate the molar enthalpy of solidification for gallium.

now i know the two formulas (delta)H=n(delta)H and q=mc(delta)t

im just having trouble getting the answer the book has: -5.54kJ/mole i get like -2.something Kj/mole.

can someone please help me?

[enahs]

Show your calculations, I get 5.5 kJ/mol.

[paukwa]

ya i was an idiot i used the gallium's mass to calculate the molar enthalpy and then i also forgot that when you solve the molar enthalpy it is in jules and not kilojules, thanks for your help tho

[paukwa]

but would it be -5.5Kj because the reaction is exothermic, cause the gallium is going from liquid to solid and is losing energy?

[enahs]

Yes, I was just making a brief statement about the numerical part being correct with quick calculations and round, etc.
 

[paukwa]

o ok sorry! just wanted to make sure thanks alot