[aziza]

Hello!

I'd like to know if I'm doing this question right and I'm really hoping someone will give me some feedback:

Q:  A sample of zinc is placed in an ice calorimeter, where it is determined that 3.68KJ of heat are released per mL change in the volume of the ice/water mixture.  If 0.0657g of zinc causes a decrease of 0.109mL in the ice/water volume of the calorimeter, what is the enthalpy change, per mole of zin, for the following reaction per mole of zinc.

Reaction: Zn(s) + 2H+(aq) --> Zn2+(aq) + H2(g)


Here's my work:

Mole Zn: 0.0657g/65.39g/mol = 1.00x10^-3 mol

-3.68KJ/mL x 0.109mL = -0.401KJ (enthalpy change calorimeter)

At constant pressure, deltaH = q

q calorimeter = -q rxn
therefore q rxn = 0.401KJ

deltaH rxn = 0.401KJ x (1.00x10^-3 mol)
= 4.01x10^-4 KJ/mol

Is this done correctly?  It seems wrong....

Regards,

Michelle

[LQ43]

what is the enthalpy change, per mole of zin, for the following reaction per mole of zinc.


deltaH rxn = 0.401KJ x (1.00x10^-3 mol)
= 4.01x10^-4 KJ/mol

Is this done correctly?  It seems wrong....

just at the end there, the question asks for enthalpy change PER mole of zinc....gave a hint in your calculation above....

[aziza]

Oh of course, duh!
Thank you so much