Question

A)
A scientist measures the standard enthalpy change for the following reaction to be -209.6 kJ :
CO(g) + 3 H₂(g)------>CH₄(g) + H₂O(g)
Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of CH₄(g) is________ kJ/mol

B)A scientist measures the standard enthalpy change for the following reaction to be -577.3 kJ:
H₂CO(g) + O₂(g)-------->CO₂(g) + H₂O(l)
Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of H₂O(l) is __________kJ/mol.

C)
A scientist measures the standard enthalpy change for the following reaction to be -346.4 kJ :
2Na(s) + 2 H₂O(l)------->2NaOH(aq) + H₂(g)
Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of H₂O(l) is_________ kJ/mol.

All three problems are a set of one homework problem for my assignment, so please answer all three. Thank you!