Answer:
Change in enthalpy is -51.072 kJ/mol.
Explanation:
Molar mass of NaOH = 39.997 g/mol
So, 4.98 g of NaOH = [tex]\frac{4.98}{39.997}[/tex] moles of NaOH = 0.125 moles of NaOH
Total mass of solution = (4.98+52.79) g = 57.77 g
Heat consumed by solution = [tex](m_{solution}\times C_{solution}\times \Delta T_{solution})[/tex] , where m is mass C is specific heat and [tex]\Delta T[/tex] is change in temperature.
So, heat consumed by solution = [tex][57.77g\times 4.186\frac{J}{g.^{0}\textrm{C}}\times (50.1-23.7)^{0}\textrm{C}][/tex]
= 6384 J
It is an exothermic process as temperature increases during dissolution. Hence change in enthalpy should be negative.
Change in enthalpy = -(heat consumed by solution)/(no. of moles of NaOH)
= [tex]-\frac{6384J}{0.125mol}=-51072J/mol=-51.072kJ/mol[/tex]
