20cm3 of 0.500moldm-3 H2SO4 was consumed to neutralize 50cm3 of 0.400moldm-3 NaOH. The temperature of the system is increased by 36 degree C. The heat capacity of the calorie meter was 39 JK-1, and the heat capacityof the solution is 4.2JK-1. Find the enthalpy of neutralization for the reaction.
To find the enthalpy of neutralization for the reaction, we need to calculate the heat transferred during the reaction. The formula for heat transfer is:
Q = mcΔT
Where:
Q is the heat transferred (in joules)
m is the mass of the solution (in grams)
c is the specific heat capacity of the solution (in J/g°C)
ΔT is the change in temperature (in °C)
First, let's calculate the mass of the solution:
Mass of solution = Volume of solution x Density of solution
Given that the volume of the solution is 50 cm³, we can assume that the density of the solution is the same as water, which is approximately 1 g/cm³. Therefore:
Mass of solution = 50 g
Next, let's calculate the change in temperature:
ΔT = Temperature increase - Initial temperature
Given that the temperature of the system increased by 36°C, and we assume the initial temperature was 25°C:
ΔT = 36°C - 25°C = 11°C
Now, let's calculate the heat transferred (Q):
Q = mcΔT
Q = (mass of solution + heat capacity of calorimeter) x ΔT
Given that the heat capacity of the calorimeter is 39 J/K and the mass of the solution is 50 g, and the specific heat capacity of the solution is 4.2 J/g°C:
Q = (50 g + 39 J/K) x 11°C
Now, we need to convert the heat transferred from joules to kilojoules:
Q (in kJ) = Q (in J) / 1000
Finally, the enthalpy of neutralization (ΔH) is equal to the heat transferred (Q) divided by the number of moles of the limiting reactant:
Number of moles of H₂SO₄ = concentration x volume
= 0.500 mol/dm³ x 0.020 dm³
Number of moles of NaOH = concentration x volume
= 0.400 mol/dm³ x 0.050 dm³
The enthalpy of neutralization can be calculated using the equation:
ΔH = Q / (number of moles of limiting reactant)
Now, substitute the values into the equation to find the enthalpy of neutralization.