Calculating Enthalpy of Neutralization in Calorimetry Experiment

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In summary, the question is asking for the enthalpy of neutralization of acetic acid in a calorimetry experiment where it is mixed with sodium hydroxide. The given information includes the volume and concentration of the solutions, the temperature change, the heat capacity of the calorimeter, and the density of the resulting solution. To solve for the enthalpy of neutralization, the specific heat capacity of sodium acetate is also needed. From these values, the enthalpy of neutralization is calculated to be -50.2 kJ/mol.
  • #1
boredooom
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Could I get a solution to this question?

In a laboratory experiment in calorimetry, 100 mL of 0.500 M of acetic acid is mixed with 100 mL of 0.500 M sodium hydroxide in a calorimeter. The temperature rises from 25.00 C to 27.55 C. The heat capacity of the calorimeter is 150.48 J/C, and the density of the resulting solution is 1.034g/mL. Given that the specific heat capacity of 0.250 M of sodium acetate is 4.034 Jg-1C-1, calculate the enthalpy of neutralization of acetic acid.

Answer: -50.2kJ/mol
 
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  • #2
boredooom said:
Could I get a solution to this question?

In a laboratory experiment in calorimetry, 100 mL of 0.500 M of acetic acid is mixed with 100 mL of 0.500 M sodium hydroxide in a calorimeter. The temperature rises from 25.00 C to 27.55 C. The heat capacity of the calorimeter is 150.48 J/C, and the density of the resulting solution is 1.034g/mL. Given that the specific heat capacity of 0.250 M of sodium acetate is 4.034 Jg-1C-1, calculate the enthalpy of neutralization of acetic acid.

Answer: -50.2kJ/mol

perhaps you should explain what you've done so far. We don't help you with your homework unless you demonstrate you have at least tried to do it yourself.
 
  • #3


To calculate the enthalpy of neutralization in this calorimetry experiment, we can use the equation Q = m x c x ΔT, where Q is the heat released or absorbed, m is the mass of the solution, c is the specific heat capacity, and ΔT is the change in temperature. In this case, the heat released is equal to the heat gained by the calorimeter and the resulting solution.

First, we need to calculate the mass of the resulting solution. This can be found by adding the masses of acetic acid and sodium hydroxide used, which is 100 mL each, and then multiplying by the density of the solution.

Mass = (100 mL + 100 mL) x (1.034 g/mL) = 206.8 g

Next, we can calculate the heat released by the reaction using the given data:

Q = (206.8 g) x (4.034 J/gC) x (27.55 C - 25.00 C) = 2115.2 J

Since the heat released by the reaction is equal to the heat gained by the calorimeter and the resulting solution, we can use this value to calculate the enthalpy of neutralization:

ΔH = -Q/ n

Where n is the number of moles of acid or base used in the reaction. In this case, n = 0.100 L x 0.500 mol/L = 0.05 mol (since the reaction is 1:1).

ΔH = -2115.2 J / 0.05 mol = -42,304 J/mol = -42.3 kJ/mol

However, this value is for the specific heat capacity of sodium acetate at 0.250 M. To get the enthalpy of neutralization for acetic acid, we need to adjust for the concentration difference.

Since the specific heat capacity is proportional to the concentration, we can use the equation c1/c2 = ΔH1/ΔH2, where c1 and c2 are the concentrations and ΔH1 and ΔH2 are the corresponding enthalpies.

c1/c2 = (0.250 mol/L) / (0.500 mol/L) = 0.5

Thus, we can adjust the enthalpy of neutralization calculated earlier by multiplying by 0.5.

ΔH = -42.3 kJ/mol
 

1. What is enthalpy and why is it important in science?

Enthalpy is a thermodynamic property that represents the total energy of a system. It is important in science because it helps us understand and predict how energy will move and change in various chemical and physical processes.

2. How do you solve an enthalpy problem?

To solve an enthalpy problem, you will need to use the enthalpy equation: H = U + PV, where H is enthalpy, U is internal energy, P is pressure, and V is volume. You will also need to know the specific heat capacity of the substances involved and the change in temperature. By plugging in these values and following the correct sign conventions, you can calculate the change in enthalpy for the system.

3. What are the units of enthalpy?

The units of enthalpy are joules (J) in the SI system and calories (cal) in the cgs system. However, it is more commonly expressed in kilojoules (kJ) or kilocalories (kcal) for convenience.

4. How is enthalpy related to heat?

Enthalpy is related to heat through the equation Q = mCΔT, where Q is heat, m is mass, C is specific heat capacity, and ΔT is the change in temperature. Enthalpy is a measure of the total heat content of a system, so it takes into account both the temperature change and the mass of the substance.

5. What are some real-life applications of enthalpy?

Enthalpy is used in various industries, such as chemical processing, power generation, and refrigeration. It is also essential in understanding and predicting weather patterns and in designing heating and cooling systems for buildings. In biochemistry, enthalpy is used to study metabolic reactions and in food science, it is used to determine the calorie content of foods.

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