Answer to Question #171940 in General Chemistry for Sukhi

Question

HCl is a corrosive colourless gas that dissolves readily in water.

Aqueous HCl reacts with NaOH to form water and NaCl. In a simple

calorimeter, a 100.00 mL sample of 0.415 mol/L HCl(aq) is mixed

with 50.00 mL of excess NaOH(aq). During the reaction, there is a

rise in temperature by 4.83 °C. Calculate the molar enthalpy change

(in kJ/mol) for the above reaction. SHOW ALL YOUR WORK.

Answer 1

no of moles of HCl = 0.415 x 100 x10^-3 = 0.0415 mole of HCl

HCl + NaOH = NaCl + H²O ΔH = --55KJ/mol

ΔH neutralization = -55KJ/ mol x 0.0415 mol= 2.29 KJ/mol