Compound B is burned in a bomb calorimeter that contains 1.50 liters of water. When I burned 50.0 grams of compound B in the calorimeter, the temperature rise of the water in the calorimeter was 35.0 degrees C. If the heat of combustion of compound B is 2,150 kJ/mol, what is the molar mass of compound B?
amount of heat released per gram:
35*1.50*4.186kJ /50.0=4.395kJ/gram
molar mass=2150kJ/mole /4.395kj/gram
=499 grams/mole
check my calcs.
How did u get 4.186 kj?
That's the specific heat for H2O.
q = m*c*delta T.
To find the molar mass of Compound B, we need to use the equation:
Molar mass (in g/mol) = (Heat released per mole of Compound B) / (Temperature rise of water in the calorimeter)
First, let's calculate the heat released per mole of Compound B.
We know that 50.0 grams of Compound B were burnt in the calorimeter. We need to convert this mass into moles. To do that, we'll use the molar mass of Compound B.
The molar mass of Compound B can be calculated using the equation:
molar mass = (mass of compound) / (moles of compound)
So, we can rearrange the equation to find moles of compound:
moles of compound = (mass of compound) / (molar mass)
Since we have 50.0 grams of Compound B, we will divide this by the moles of compound to get the moles.
Next, let's calculate the heat released per mole of Compound B.
We know that the heat of combustion of Compound B is 2,150 kJ/mol.
To convert this to joules (J), we need to multiply it by 1,000 because there are 1,000 joules in 1 kilojoule.
Now, let's calculate the temperature rise of the water in the calorimeter.
We know that the temperature rise is 35.0 degrees Celsius.
Finally, we can use the formula to calculate the heat released per mole of Compound B:
Heat released per mole of Compound B = (Temperature rise of water) x (Volume of water) x (Specific heat capacity of water)
The specific heat capacity of water is 4.184 J/g°C.
Since we know the temperature rise is 35.0°C, the volume of water is 1.50 L, and the specific heat capacity of water is 4.184 J/g°C, we can multiply these values together to find the heat released per mole of Compound B.
After finding the heat released per mole of Compound B, we can now calculate the molar mass by dividing the heat released per mole by the temperature rise of water.
Molar mass (in g/mol) = (Heat released per mole of Compound B) / (Temperature rise of water)
By following these steps, we can find the molar mass of Compound B.