The standard enthalpy of combustion of ethene gas, C2H4(g), is -1411.1 kJ/mol at 298 K. Given the following enthalpies of formation, calculate ΔHf° for C2H4(g). CO2(g) -393.5 kJ/mol
H2O(l) -285.9 kJ/mol

Phosphorous can form an ion called phosphide, which has the formula p3−. this ion can form an ion called phosphide, which has the formula p3−. this ion properties very similar to those of pforms when a phosphorus atom loses three protonsis called a cationcontains 18 electrons