it’s the first or last one i believe
Combustion can be defined as the reaction of a compound with oxygen. The enthalpy of combustion of octane is
for
.
<h3>What is the enthalpy of reaction?</h3>
The enthalpy of reaction is the amount of heat energy absorbed or lost by the molecules in the chemical reaction.
The enthalpy of combustion is the amount of heat energy released by the compound in the reaction with oxygen.
The reaction in which heat is liberated with the reaction of a compound with oxygen has an enthalpy of combustion, equivalent to the enthalpy of reaction.
The combustion of octane can be given as:

Thus, the reaction has combustion energy equivalent to the enthalpy of the reaction is
. Thus, option B is correct.
Learn more about enthalpy of reaction, here:
brainly.com/question/1657608
There is a missing portion of this question which shows the reaction that needs balancing:
"In a balanced equation, the same number of each kind of atom is shown on each side of the equation. Calculate the number of iron (Fe), oxygen (O), and carbon atoms (C).
Fe2O3+ 3CO --> 2Fe + 3CO<span>2
</span><span>Based on these values, is the equation balanced?</span><span>"
</span>
To check if this equation is balanced we simply compare the number of each element on each side of the equation.
On the reactant side of the equation we have:
2 Fe atoms
6 O atoms
3 C atoms
On the product side of the equation we have:
2 Fe atoms
6 O atoms
3 C atoms
Therefore, both side of the reaction have the correct and equal number of each atom, so the equation is balanced.
Answer:
p-fluoronitrobenzene and sodium phenoxide is more appropriate
Explanation:
An ipso substitution is required to form p-nitrophenyl phenyl ether.
For this ipso substitution, an alkoxide anion needs to attack as a nucleophile at the carbon atom attached to fluorine atom and thereby substitute that F atom.
p-nitrophenoxide is an weak nucleophile as compared to phenoxide due to presence of electron withdrawing resonating effect of nitro group at para position.
p-fluoronitrobenzene is a good choice for nucleophilic attack by alkoxide anion as compared to fluorobenzene due to higher positive charge density at carbon atom directly attached to F atom. Higher positive charge density arises due to presence of electron withdrawing resonating effect og nitro group at para position.
So, p-fluoronitrobenzene and sodium phenoxide is more appropriate