Calculating Calorimeter Heat Capacity for Naphthalene Combustion

  • Thread starter Thread starter Taryn
  • Start date Start date
  • Tags Tags
    Heat
AI Thread Summary
To calculate the calorimeter heat capacity for naphthalene combustion, the user burned 136.8 mg of naphthalene, resulting in a temperature increase of 3.29 °C. They initially calculated the number of moles of naphthalene but struggled to determine the correct delta H value, questioning the accuracy of the heat of combustion they found online. The heat of combustion for naphthalene is noted as 5156 kJ/mol, which should be equated to the heat gained by the calorimeter. Despite attempts to apply this information, the user continued to encounter errors in their calculations. They plan to seek assistance from their lecturer for further clarification.
Taryn
Messages
63
Reaction score
0
You burn 136.8 mg of naphthalene in a calorimeter and the temperature of the calorimeter rises by 3.29 oC. Determine the calorimeter heat capacity in J K-1. The molar mass of naphthalene is 128.18 g mol-1

This is a question from a quiz I have to do.
this is wat I did.
Ccal=delta H/delta n=0.1368g/128.18g/mol
=1.06E-3moles

I don't know how to calc delta H from this info but I looked it up on the net and found 72.6+0.6kJ/mol.
Thats not right is it coz when I put this information in the formula
Ccal=((72.6+0.6)x1000j/molx1.06E-3)/(3.29+273.15)

I got it wrong... any help?
Does anyone know if my value for entropy of napthalene is right?
 
Physics news on Phys.org
Taryn said:
You burn 136.8 mg of naphthalene in a calorimeter and the temperature of the calorimeter rises by 3.29 oC. Determine the calorimeter heat capacity in J K-1. The molar mass of naphthalene is 128.18 g mol-1

This is a question from a quiz I have to do.
this is wat I did.
Ccal=delta H/delta n=0.1368g/128.18g/mol
=1.06E-3moles

I don't know how to calc delta H from this info but I looked it up on the net and found 72.6+0.6kJ/mol.
Thats not right is it coz when I put this information in the formula
Ccal=((72.6+0.6)x1000j/molx1.06E-3)/(3.29+273.15)

I got it wrong... any help?
Does anyone know if my value for entropy of napthalene is right?

heat of combustion of naphthelene=5156 kJ/mole. I think u may equate this to heat gained by calorimeter.
 
Thanks I will try that!
 
Yeah I just tried to use that and still got it wrong its so frustrating! I will go and see my lecturer now and hopefully he can help. Can u see anything wrong with my process?
 
Thread 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
Thread 'Correct statement about a reservoir with an outlet pipe'
The answer to this question is statements (ii) and (iv) are correct. (i) This is FALSE because the speed of water in the tap is greater than speed at the water surface (ii) I don't even understand this statement. What does the "seal" part have to do with water flowing out? Won't the water still flow out through the tap until the tank is empty whether the reservoir is sealed or not? (iii) In my opinion, this statement would be correct. Increasing the gravitational potential energy of the...
Back
Top