Suppose 300.0 mL of 0.50 M HCl and 300.0 mL of 0.50 M NaOH, both initially at 22.0°C, are mixed in a thermos flask. When the reaction is complete, the temperature is 25.4°C. Assuming that the solutions have the same heat capacity as pure water, compute the heat released (in kJ).
q = mass H2O x specific heat H2O x (Tfinal-Tinitial)
Substitute and solve for q in J and convert to kJ. 600 mL is 600 g for mass.
To compute the heat released during the reaction, we can use the equation:
q = m * C * ΔT
Where:
- q is the heat released or absorbed
- m is the mass of the solution
- C is the specific heat capacity of the solution
- ΔT is the change in temperature
First, we need to calculate the mass of the solution. This can be done by multiplying the volume of the solution by the density of water:
Density of water = 1 g/mL
Mass of the solution = volume of the solution * density of water
Since we have 300.0 mL of HCl and 300.0 mL of NaOH, the total volume of the solution is 300.0 mL + 300.0 mL = 600.0 mL.
Mass of the solution = 600.0 mL * 1 g/mL
Now, let's convert the mass of the solution from grams to kilograms for convenience:
Mass of the solution = 600.0 mL * 1 g/mL * (1 kg / 1000 g)
Next, we need to calculate the change in temperature (ΔT). The initial temperature is 22.0°C, and the final temperature is 25.4°C. So,
ΔT = final temperature - initial temperature
Now, we can calculate the heat released (q) using the equation mentioned above:
q = mass of the solution * specific heat capacity of water * ΔT
The specific heat capacity of water is about 4.18 J/g°C. However, we want the answer in kJ, so we need to convert it:
1 kJ = 1000 J
Therefore, the heat released (q) can be calculated by substituting the known values into the equation and performing the necessary conversions.