zakarycrane1794 zakarycrane1794 09-04-2024 Chemistry contestada Which of the substances have a standard heat of formation ( ΔH°f ) of zero?a. Cl₂ (g) at 2 atmb. Fe at 1200 °Cc. C₂H₆ (g) at standard conditionsd. O₂(g) at 25.0°C and 1 atm