Karst topography can cause drinking water to become more polluted
<span>Gamma rays, X-rays, and UV radiation is reflected by the ozone layer.</span>
Answer:
A. (1/2) N₂(g) + O₂ (g) → NO₂(g)
Explanation:
H°rxn = ∑n*H°f, products - ∑n*H°f, reactants (where n is the number of moles)
H°f is the enthalpy of formation at standard conditions, and it's 0 by the compounds formed by a single element at its atmospheric phase. So, to H°rxn = H°f, products, the number of moles of the product must be 1 and the H°f, reactants must be 0.
Both conditions are only satisfied in letter A.
In letter B, the reactants H and Br are not in the molecule formula, so their H°f is not 0. The mase happens in letter C for O, and in letter E for H. In letter D, 2 moles of the product are being formed.