Hess’s law A -> B Delta H= +30kJ
B -> C Delta H= +60kJ
A.) Use Hess’s law to calculate the enthalpy change for the reaction A -> C
B.) Construct an enthalpy diagram for substances A, B, and C and show how Hess’s law applies.

Achemistry student weighs out 0.306 g of citric acid (h3c6h5o7), a triprotic acid, into a 250 ml volumetric flask and dilutes to the mark with distilled water. he plans to titrate the acid with 0.1000 m naoh solution. calculate the volume of naoh solution the student will need to add to reach the final equivalence point. be sure your answer has the correct number of significant digits.