Determine the molar enthalpy of reaction for the reaction of magnesium with hydrochloric acid.
Mass of calorimeter + hydrochloric acid is 58.47g
Mass of calorimeter is 3.53g
Initial temperature of the solution is 21 degrees celsius
Mass of the magnesium is 0.17g
Finial temperature of the solution is 35 degrees celsius
To determine the molar enthalpy of reaction for the reaction of magnesium with hydrochloric acid, we can use the equation:
ΔH = q / n
where:
ΔH is the molar enthalpy of reaction (in kJ/mol)
q is the heat transferred (in J)
n is the number of moles of the limiting reactant in the reaction
First, let's calculate the heat transferred (q):
q = (mcalorimeter + macid) * C * ΔT
where:
mcalorimeter is the mass of the calorimeter (in g)
macid is the mass of the hydrochloric acid (in g)
C is the specific heat capacity of the solution (assumed to be 4.18 J/g°C)
ΔT is the change in temperature (in °C)
mcalorimeter = 3.53g
macid = 58.47g - 3.53g = 54.94g
C = 4.18 J/g°C
ΔT = 35°C - 21°C = 14°C
Substituting the values into the equation:
q = (3.53g + 54.94g) * 4.18 J/g°C * 14°C
q = 2409.14 J
Next, let's calculate the number of moles of magnesium used in the reaction:
n = m / M
where:
m is the mass of magnesium (in g)
M is the molar mass of magnesium (approximately 24.31 g/mol)
m = 0.17g
M = 24.31 g/mol
n = 0.17g / 24.31 g/mol
n ≈ 0.007 mol
Now, we can calculate the molar enthalpy of reaction (ΔH):
ΔH = q / n
ΔH = 2409.14 J / 0.007 mol
ΔH ≈ 344,162 J/mol
Converting J to kJ:
ΔH ≈ 344.162 kJ/mol
Therefore, the molar enthalpy of reaction for the reaction of magnesium with hydrochloric acid is approximately 344.162 kJ/mol.
To determine the molar enthalpy of reaction for the reaction of magnesium with hydrochloric acid, follow these steps:
Step 1: Calculate the mass of hydrochloric acid used:
Mass of hydrochloric acid = Mass of calorimeter + hydrochloric acid - Mass of calorimeter
Mass of hydrochloric acid = 58.47 g - 3.53 g
Mass of hydrochloric acid = 54.94 g
Step 2: Convert the mass of magnesium to moles:
Moles of magnesium = Mass of magnesium / molar mass of magnesium
Molar mass of magnesium = 24.31 g/mol
Moles of magnesium = 0.17 g / 24.31 g/mol
Moles of magnesium = 0.007 mol
Step 3: Calculate the change in temperature:
Change in temperature = Final temperature - Initial temperature
Change in temperature = 35 °C - 21 °C
Change in temperature = 14 °C
Step 4: Calculate the molar enthalpy of reaction using the equation:
Molar enthalpy of reaction = (Heat gained or lost / Moles of magnesium)
Step 5: Calculate the heat gained or lost by the solution:
Heat gained or lost = Mass of solution × specific heat capacity of water × Change in temperature
Mass of solution = Mass of hydrochloric acid + Mass of water
Assuming the specific heat capacity of water is 4.18 J/g°C:
Mass of solution = 54.94 g
Heat gained or lost = 54.94 g × 4.18 J/g°C × 14 °C
Step 6: Calculate the molar enthalpy of reaction:
Molar enthalpy of reaction = (54.94 g × 4.18 J/g°C × 14 °C) / 0.007 mol
Now, you can solve the equation to find the molar enthalpy of reaction.
To determine the molar enthalpy of reaction for the reaction of magnesium with hydrochloric acid, follow these steps:
Step 1: Calculate the heat absorbed by the calorimeter and the hydrochloric acid.
- Mass of the calorimeter and hydrochloric acid = 58.47g
- Initial temperature of the solution (calorimeter) = 21°C
- Final temperature of the solution (calorimeter) = 35°C
The heat absorbed by the calorimeter and hydrochloric acid can be determined using the formula:
q = m * C * ΔT
where:
- q is the heat absorbed
- m is the mass of the substance (calorimeter + hydrochloric acid)
- C is the specific heat capacity of the substance
- ΔT is the change in temperature
Step 2: Calculate the heat released by the magnesium and the reaction.
- Mass of the calorimeter = 3.53g
- Mass of the magnesium = 0.17g
- Final temperature of the solution (calorimeter) = 35°C
The heat released by the reaction can be determined by subtracting the heat absorbed by the calorimeter from the total heat absorbed:
Heat released by the reaction (q_reaction) = Total heat absorbed - Heat absorbed by the calorimeter
Step 3: Calculate the molar enthalpy of reaction.
- Molar mass of magnesium (Mg) = 24.31 g/mol
- Number of moles of magnesium (n) = Mass of magnesium / Molar mass of magnesium
The molar enthalpy of reaction (ΔH) can be calculated using the formula:
ΔH = q_reaction / n
where:
- ΔH is the molar enthalpy of reaction
- q_reaction is the total heat released by the reaction
- n is the number of moles of the limiting reactant (in this case, magnesium)
By following these steps and plugging in the given values, you can calculate the molar enthalpy of reaction for the reaction of magnesium with hydrochloric acid.