Answer: 48.6 kJ/mol
Explanation:
The balanced chemical reaction is,
The expression for enthalpy change is,
where,
n = number of moles
(as heat of formation of substances in their standard state is zero
Now put all the given values in this expression, we get
Therefore, the enthalpy change for benzene is 48.6 kJ/mol
25.9 kJ/mol. (3 sig. fig. as in the heat capacity.)
<h3>Explanation</h3>The process:
.
How many moles of this process?
Relative atomic mass from a modern periodic table:
Molar mass of :
.
Number of moles of the process = Number of moles of dissolved:
.
What's the enthalpy change of this process?
for
. By convention, the enthalpy change
measures the energy change for each mole of a process.
.
The heat capacity is the least accurate number in these calculation. It comes with three significant figures. As a result, round the final result to three significant figures. However, make sure you keep at least one additional figure to minimize the risk of rounding errors during the calculation.