Respuesta :
Answer:
The enthalpy change for the reaction per mole of CsOH is -56.1 kJ/mol
Explanation:
Step 1: Data given
Volume of a CsOH solution = 100.0 mL
Molarity of a CsOH solution = 0.200 M
Volume of HCl solution = 50.0 mL
Molarity of HCl solution = 0.400M
The temperature of both solutions before mixing was 22.50 °C, and it rises to 24.28 °C after the acid-base reaction.
Density = 1.00 g/mL
Specific heat = 4.2 J/gK = 4.2 J/g°C
Step 2: The balanced equation
CsOH + HCl → CsCl + H2O
Step 3: Calculate the energy
Q = m*c*ΔT
⇒with Q = the heat transfer = TO BE DETERMINED
⇒with m = the mass of the solution = (100+ 50 mL) * 1.00 g/mL = 150 grams
⇒with c = the specific heat of the solution = 4.2 J/g°C
⇒with ΔT = The change of temperature = T2 - T1 = 24.28 °C - 22.50 °C = 1.78 °C
Q = 150 grams * 4.2 J/g°C * 1.78 °C
Q = 1121.4 J
Step 4: Calculate moles CsOH
Moles CsOH = molarity CsOH * volume CsOH
Moles CsOH = 0.200M * 0.100 L
Moles CsOH = 0.0200 moles
Step 5: Calculate the enthalpy change for the reaction per mole of CsOH
ΔH is negative since this is an exothermic reaction
ΔH = -Q/moles
ΔH = -1121.4 J / 0.0200 moles
ΔH = -56070 J/mol = -56.1 kJ/mol
The enthalpy change for the reaction per mole of CsOH is -56.1 kJ/mol
