Three Questions

Recently Iv'e learned about Hess's Law. We did a lab today that measure the enthalpys of different reactions; HCl and NaOH, NaOh and NH4Cl, and HCl and NH3. We measured the temperature change of two reactions and used Hess's law to determine the  the enthalpy change, delta H of a third reaction. I am understanding the calculations on how to figure out enthalpy and Hess's law. I hope to keep up my studies in this class and get at least a C in this class.