<span>the right answer is .C )<span>Matthew was right because RNA is single-stranded while DNA is double-stranded.</span></span>
For this problem, we use the Hess' Law.
ΔHrxn = ∑(ν*Hf of products) - ∑(ν*Hf of reactants)
The ν represents the corresponding stoichiometric coefficients of the substances, while Hf is the heat of formation. For pure elements, Hf = 0.
Hf of Al₂O₃ = <span>−1676.4 kJ/mol
</span>Hf of Fe₂O₃ = <span>-826.0 kJ/mol
Thus,
</span>ΔHrxn = 1*−1676.4 kJ/mol + 1*-826.0 kJ/mol
<em>ΔHrxn = -2502.4 kJ/mol</em>
Just count the number C’s and H’s
A. The reactants that run out first
Easy!
I suggest watching Martin Shkerli YouTube channel. He has a ton of videos on chemistry and is very helpful.