To which one of the following reactions occurring at 25°c does the symbol δh°f[h2so4(l)] refer? a)2 h(g) + s(g) + 4 o(g) h2so4(l)b)h2(g) + s(g) + 2 o2(g) h2so4(l)c)h2so4(l)h2(g) + s(rhombic) + 2 o2(g)d)h2so4(l)2 h(g) + s(rhombic)+ 4 o(g)e)h2(g) + s(rhombic) + 2 o2(g)h2so4(l)