Which of the following is not correct regarding standard enthalpy of formation `(Delta_(f)H^(0))` at `298K`.
`Delta_(f)H^(0)`(C, diamond)`>0`
`Delta_(f)H^(0)(H^(+),aq)=0`
`Delta_(f)H^(0)CO_(2)(g)=0`
`Delta_(f)H^(0)`(S, orthorhombic)`=0`