The molar heat of combustion for phenol

AI Thread Summary
The discussion focuses on calculating the molar heat of combustion for phenol using a calorimeter. The initial calculations involved determining the number of moles of phenol burned and applying the heat capacity formula. A clarification was provided regarding the use of temperature change, confirming that the Celsius and Kelvin scales are equivalent for temperature differences. After addressing the confusion, the original poster successfully arrived at the correct answer. The interaction highlights the importance of understanding thermodynamic principles in calorimetry.
Taryn
Messages
63
Reaction score
0
You burn 103.4 mg of phenol in a calorimeter of heat capacity 1,483 J K-1 and the temperature rises by 1.83 oC. Determine the molar heat of combustion for phenol in kJ mol-1. The molar mass of phenol is 94.12 g mol-1

Ccal=deltaH/ deltaT

This is what I did.
n=.1034/94.12
=1.09859E-3mol

deltaH=(1483J/K*274.98K)/1.09859E-3
deltaH=371198.84kJ/mol

What did I do wrong... any help would be appreciated. thanks!
 
Physics news on Phys.org
Your equation calls for deltaT, so that means the change in temperature.

You were given deltaT in the question. Remember that 1 degree Celcius = 1 degree Kelvin, so the difference of two temperatures will be the same on either scale.
 
Hey Thanks... that's helpful... I got the answer to the answer right thanks a heap!
 
Thread 'Voltmeter readings for this circuit with switches'

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...
View full post »
Thread 'Struggling to make relation between elastic force and height'

Thread 'Struggling to make relation between elastic force and height'

Hello guys this is what I tried so far. I used the UTS to calculate the force it needs when the rope tears. My idea was to make a relationship/ function that would give me the force depending on height. Yeah i couldnt find a way to solve it. I also thought about how I could use hooks law (how it was given to me in my script) with the thought of instead of having two part of a rope id have one singular rope from the middle to the top where I could find the difference in height. But the...
View full post »

Similar threads

Why is this calculation of the enthelpy of combustion wrong?
Replies
4
Views
2K
Why Must a Calorimeter Be Saturated with Water Vapor?
Replies
6
Views
2K
Chemistry Does Combusting Different Amounts of Propane Change Final Temperature?
Replies
5
Views
2K
Thermodynamics: calculating work question
Replies
6
Views
2K
Chemistry Understanding the calculation of enthalpy of the formation of benzene
Replies
3
Views
2K
What Is the Molar Heat of Transformation for Phosphine at 30.29 K?
Replies
1
Views
1K
What is the molar heat capacity of an ideal gas at constant pressure and volume?
Replies
5
Views
3K
Calculating Heat Capacity in a Bomb Calorimeter using Combustion of Toluene
Replies
5
Views
4K
Calculate the molar heat of combustion of anthracene
Replies
3
Views
7K
What Is the Entropy Change When Ice Melts in Hot Water?
Replies
2
Views
2K

Hot Threads

Recent Insights

Back
Top