calculate the enthalpy change for the reaction p4o6(s) 2o2(g)→p4o10(s)p4o6(s) 2o2(g)→p4o10(s) given the following enthalpies of reaction: p4(s) 3o2(g)→p4o6(s),δhp4(s) 5o2(g)→p4o10(s),δh