madey21
Answered

Given the reaction:

[tex]\[ 2H_2(g) + O_2(g) \rightarrow 2H_2O(g) \quad \Delta H^\circ = -484.0 \frac{kJ}{mol} \][/tex]

This reaction is reversed to connect with the goal reaction. What is the enthalpy for the modified reaction?

Enter either a "+" or "-" sign AND the magnitude. Use significant figures.



Answer :

Certainly! Let's start by understanding that enthalpy change ([tex]\(\Delta H\)[/tex]) for a reaction is a measure of the heat released or absorbed during the process. In the given problem, we have the following chemical reaction:

[tex]\[ 2 H_2(g) + O_2(g) \rightarrow 2 H_2O(g) \][/tex]

with an enthalpy change:

[tex]\[ \Delta H^{\circ} = -484.0 \frac{ kJ }{ mol } \][/tex]

This indicates that the reaction releases 484.0 kJ of energy per mole of reaction, making it an exothermic reaction (since the sign of [tex]\(\Delta H\)[/tex] is negative).

However, the problem states that we need the enthalpy change for the reversed reaction. Reversing a chemical reaction involves reversing the sign of the enthalpy change because the direction of heat flow is reversed.

In the forward reaction:

[tex]\[ 2 H_2(g) + O_2(g) \rightarrow 2 H_2O(g) \][/tex]

[tex]\[ \Delta H^{\circ} = -484.0 \frac{ kJ }{ mol } \][/tex]

In the reverse reaction:

[tex]\[ 2 H_2O(g) \rightarrow 2 H_2(g) + O_2(g) \][/tex]

the enthalpy change becomes:

[tex]\[ \Delta H^{\circ} = +484.0 \frac{ kJ }{ mol } \][/tex]

This means that 484.0 kJ per mole of energy is absorbed for the reversed process, making it an endothermic reaction (since the sign of [tex]\(\Delta H\)[/tex] is positive).

Therefore, the enthalpy for the modified reaction is:

[tex]\[ +484.0 \, \frac{kJ}{mol} \][/tex]

Hence the final answer is [tex]\( +484.0 \, kJ/mol \)[/tex], considering the appropriate significant figures.