Question

Part A Manganese reacts with hydrochloric acid to produce manganese(II) chloride and hydrogen gas. Mn(s) + 2 HCl(aq) + MnCl, (aq) + H (9) When 0.620 g Mn is combined with enough hydrochloric acid to make 100.0 mL of solution in a coffee-cup calorimeter, all of the Mn reacts, raising the temperature of the solution from 23.5°C to 28.6 °C. Find AHxn for the reaction as written. (Assume that the specific heat capacity of the solution is 4.18 J/g °C and the density is 1.00 g/mL.) -189 kJ 0 -3.44 kJ 0 -1.17 kJ O -2.13 kJ

Answer 1

Mass of the solution= 100 mL * 1.00 g/mL = 100 g Specific heat capacity = 4.18 J/(mol.°C) Change in temperature = 28.6 – 23.5 = 5.1 °C Heat energy associated with solution = m*C * AT = 100 g * 4.18 J/(mol.°C) * 5.1 °C qsol = 2131.8 J = 2.1318 kJ At thermal equilibrium. Treaction + 9 solution = 0 Creaction =- 9solution = - 2.13 kJ Option D is the right answer