You want to determine the heat of reaction when a sodium chloride solution is formed using a 10.0 g sample of NaCl(s) and 50.0 mL of water in a coffee cup calorimeter. Which of the following equations would you use? Assume the specific heat of the solution is the same as the specific heat of water.

A. q = [(10.0 g)(4.18 J/g K)(Tf - Ti)]/[10.0 g/(58.44 g/mol)]
B. q = (60.0 g)(4.18 J/g K)(Tf - Ti)
C. q = [(60.0 g)(4.18 J/g K)(Tf - Ti)]/[10.0 g/(58.44 g/mol)]
D. q = (50.0 g)(4.18 J/g K)(Ti - Tf)
E. q = (60.0 g)(4.18 J/g K)(Ti - Tf)

Question

You want to determine the heat of reaction when a sodium chloride solution is formed using a 10.0 g sample of NaCl(s) and 50.0 mL of water in a coffee cup calorimeter. Which of the following equations would you use? Assume the specific heat of the solution is the same as the specific heat of water.

 		A.	q = [(10.0 g)(4.18 J/g  K)(Tf - Ti)]/[10.0 g/(58.44 g/mol)]
 		B.	q = (60.0 g)(4.18 J/g  K)(Tf - Ti)
 		C.	q = [(60.0 g)(4.18 J/g  K)(Tf - Ti)]/[10.0 g/(58.44 g/mol)]
 		D.	q = (50.0 g)(4.18 J/g  K)(Ti - Tf)
 		E.	q = (60.0 g)(4.18 J/g  K)(Ti - Tf)

dtan5457 · Answer

@matt101 Could you please check this out?

vera_ewing · Answer

@sweetburger Do you know the answer?

sweetburger · Answer

q=mcDeltaT so mass of the solution times the specific heat of the solution time the change in temperature. This is my best guess someone is going to have to confirm if this is correct or wrong.

vera_ewing · Answer

So which one do you think it is?

sweetburger · Answer

if i remember correctly the mass of 50ml of water would just be 50grams so 50grams of water + 10 grams of NaCl would be 60 grams so 
60g(4.18)Tf-Ti

sweetburger · Answer

I think my choice correlates to answer b.

vera_ewing · Answer

Hmmm ok thank you!

sweetburger · Answer

no problem :)