Question

When 0.572 g of compound X is burned completely in a bomb calorimeter containing 3000

g of water, a temperature rise of 0.461
◦
C is
observed. What is ∆Urxn for the combustion
of compound X? The hardware component of
the calorimeter has a heat capacity of 3.75
kJ/
◦
C. The specific heat of water is 4.184
J/g ·
◦
C, and the MW of X is 56.0 g/mol.
Answer in units of kJ/mol

Answer 1

q_v = E = [mass H2O x specific heat H2O x (Tfinal-Tinitial)] + Ccal*(Tfinal-Tinitial)

Watch the units. water is listed in J/g, Ccal is listed in kJ/C, etc.