Question

Standard book value AHan -SS. 8kJ/mol ΑνΕ ΔΗ = 479.11. Emel Plot AT vs. moles of HCl. What relationship can be displayed when a graph of AT vs. moles of HCI present is constructed? Is there a limiting reagent present? If so, identify it. What relationship can be displayed when a graph of q (heat of solution in kJ) vs. moles of HCl present is constructed? What gains heat? What loses heat? Calculate the heat of reaction (q = MCAT)? Assume that the resultant solution has a specific heat of 4.18 J/g*C. The mass is the total mass of the solution. Calculate the enthalpy of neutralization, AH neutralization. Compare your experimental value with a value that is reported in the literature (your textbook or a handbook of physical constants).

Answer 1

Higher the moles of HCl, the greater is the change in temperature ($\Delta$T).

Explanation: If more moles of HCl are added, then the temperature will increase more due to the liberation of heat in this exothermic process.

Higher the moles of HCl, the greater is the heat of reaction (q).

Explanation: q = m.c.$\Delta$T, i.e. higher the moles, the higher is the mass, hence higher will be 'q'.

The enthalpy of neutralization ($\Delta$H_{neutralization}) = -q/n, where 'q' is the heat released in the neutralization process.

Here, the calculated is given as 479.11 kJ/mol, it should be -479.11 kJ/mol; whereas the standard book value is -55.8 kJ/mol.

For sure, there is something wrong, it should not differ this much large. You please cross-check your calculations.

The calculated and standard values should be close to each other (need not to be exactly the same).