The value of delata h for the reaction below is -186 kJ. Calculate the heat Kj released from the reaction of 25g of Cl2
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The value of H° for the reaction below is -186 kJ. Calculate the heat (kJ) released when 25.0 g of HCl is produced.
H2(g) + Cl2(g) -> 2 HCl(g)
To calculate the heat released from the reaction of 25g of Cl2, we need to use the equation:
q = m * ΔH / mol
where:
q is the heat released (in kJ)
m is the mass of Cl2 (in grams)
ΔH is the enthalpy change of the reaction (in kJ)
mol is the molar mass of Cl2 (in grams/mol)
First, we need to calculate the number of moles of Cl2 using its molar mass. The molar mass of Cl2 is calculated as follows:
Molar mass of Cl2 = 2 * atomic mass of Cl
The atomic mass of Cl is approximately 35.45 g/mol.
Molar mass of Cl2 = 2 * 35.45 g/mol = 70.90 g/mol
Next, we can calculate the number of moles of Cl2:
moles of Cl2 = mass of Cl2 / molar mass of Cl2
moles of Cl2 = 25 g / 70.90 g/mol
Now we can plug the values into the heat equation:
q = (25 g) * (-186 kJ) / (70.90 g/mol)
Calculating this should give us the heat released from the reaction of 25g of Cl2.
To calculate the heat released from the reaction, we need to use the equation:
q = m * ΔH
where:
q is the heat released or absorbed (in joules or kilojoules),
m is the mass of the substance undergoing the reaction (in grams), and
ΔH is the enthalpy change of the reaction (in joules or kilojoules).
However, as given, the value of ΔH is in kilojoules, so we need to convert it to joules by multiplying it by 1000:
ΔH = -186 kJ = -186 * 1000 J = -186,000 J
Now, we can substitute the values into the equation and solve for q:
q = 25g * (-186,000 J)
q = -4,650,000 J
Therefore, the heat released from the reaction of 25g of Cl2 is -4,650,000 J, or -4,650 kJ. Since it is a negative value, it indicates that the reaction is exothermic (heat is released).