A sample of 2.08 grams of Z is dissolved into

Question

500 grams of water which is in a styrofoam
coffee cup. The temperature is monitored and
is found to rise from 25.682◦C to 25.899◦C.
What is ∆Hsolution for substance Z? Assume
no heat is lost/gained by the cup itself. The
specific heat of water is 4.184 J/g·
◦C and the
molecular weight of Z is 149 g/mol.
Answer in units of kJ/mol of Z

Answer 1

qH2O in J = mass H2O x specific heat H2O x dT.
Convert q in J to kJ.

dHZ = qH2O/g Z for dH/g Z
For dHZ in kJ/mol multiply dH/g x molar mass Z.