When .1625 g of Magnesium is burned in a bomb container that has a heat capacity of 3.03 kJ/ºC, the temperature increases by 1.252 ºC. How much heat (kJ/mol) is liberated during the burning of magnesium?
Just want to make sure I am doing this correctly:
q = ms∆T
q = (.1625g Mg) (3.03) (1.252ºC)
q = .6165 kJ/g --> kJ/mol ??
So, essentially .6164 kJ/g --> kJ/mol
.6165/24.31 = .0254 kJ/g
I didn't check the math but the method looks ok to me.
To convert the heat (q) from kJ/g to kJ/mol, you need to know the molar mass of magnesium (Mg). The molar mass of Mg is 24.31 g/mol.
First, calculate the number of moles of Mg:
moles of Mg = mass of Mg / molar mass of Mg
moles of Mg = 0.1625 g / 24.31 g/mol
moles of Mg ≈ 0.0067 mol
Then, convert the heat from kJ/g to kJ/mol:
q (kJ/mol) = q (kJ/g) * moles of Mg
q (kJ/mol) = 0.6165 kJ/g * 0.0067 mol
q (kJ/mol) ≈ 0.0041 kJ/mol
Therefore, approximately 0.0041 kJ/mol of heat is liberated during the burning of magnesium.
To find the amount of heat liberated during the burning of magnesium, we can use the formula:
q = ms∆T
In this case, q represents the heat liberated, m represents the mass of magnesium, s represents the specific heat capacity of the bomb container, and ∆T represents the change in temperature.
Let's start by calculating the values we need:
m = 0.1625 g (given)
s = 3.03 kJ/ºC (given)
∆T = 1.252 ºC (given)
Now we can substitute these values into the formula:
q = (0.1625 g) (3.03 kJ/ºC) (1.252 ºC)
q ≈ 0.61642 kJ
Therefore, the amount of heat liberated during the burning of magnesium is approximately 0.61642 kJ.
Now, to convert this value from kJ/g to kJ/mol, we need to know the molar mass of magnesium. The molar mass of magnesium is 24.31 g/mol.
To convert from grams to moles, we can use the equation:
moles = mass / molar mass
moles = 0.1625 g / 24.31 g/mol
moles ≈ 0.00668 mol
Now, we can calculate the heat liberated per mole by dividing the heat liberated by the number of moles:
kJ/mol = 0.61642 kJ / 0.00668 mol
kJ/mol ≈ 92.27 kJ/mol
Therefore, the amount of heat liberated during the burning of magnesium is approximately 92.27 kJ/mol.