Why Does Thermochemistry Equate Q of Solution to Negative Q of Reaction?

AI Thread Summary
In thermochemistry, the heat absorbed or released by a solution (Q of solution) is equal to the negative of the heat associated with the reaction (Q of reaction) due to the principle of conservation of energy. This indicates that any heat gained by the solution must be equal to the heat lost by the reaction. Additionally, a decrease in volume corresponds to a positive work value (w) because work is done on the system when the volume contracts, reflecting the energy transfer involved in the process. Understanding these relationships requires a clear grasp of the definitions and implications of the thermodynamic quantities involved.
Ritzycat
Messages
170
Reaction score
4
Hello! I have a few conceptual questions regarding thermochemistry.

In thermochemistry, why is Q of solution equal to negative Q of reaction?
Why is a volume decrease equal a POSITIVE value for w?
 
Chemistry news on Phys.org
You should be able to answer those questions yourself from a consideration of which quantities the letters in question represent and where those quantities come from - the properties that the relations are illustrating.

i.e. if a solution heats up, where did the heat energy come from?
 

Thread 'Solubility of MgSO47H2O in water'

It seems like a simple enough question: what is the solubility of epsom salt in water at 20°C? A graph or table showing how it varies with temperature would be a bonus. But upon searching the internet I have been unable to determine this with confidence. Wikipedia gives the value of 113g/100ml. But other sources disagree and I can't find a definitive source for the information. I even asked chatgpt but it couldn't be sure either. I thought, naively, that this would be easy to look up without...
View full post »

Thread 'Why does having 8 valence electrons make an element inert?'

I was introduced to the Octet Rule recently and make me wonder, why does 8 valence electrons or a full p orbital always make an element inert? What is so special with a full p orbital? Like take Calcium for an example, its outer orbital is filled but its only the s orbital thats filled so its still reactive not so much as the Alkaline metals but still pretty reactive. Can someone explain it to me? Thanks!!
View full post »

Similar threads

When do you use q=mc(Tf-Ti) versus q=c(Tf-Ti) in thermochemistry calculations?
Replies
2
Views
2K
Why would a reaction be nonspontaneous at higher temperatures?
Replies
3
Views
2K
Heat released during combustion at constant pressure vs volume
Replies
6
Views
6K
Thermochemistry relating delta H and q of surroundings
Replies
1
Views
2K
I Negative Q-value for 7Li(alpha,n) reaction
Replies
18
Views
4K
What is the difference between internal energy and enthalpy?
Replies
12
Views
3K
Question about equilibrium position
Replies
5
Views
2K
Reaction between hydrogen halide and sulfuric acid
Replies
6
Views
3K
Aluminum mystery -- Questions about elecrolysis in water
Replies
9
Views
3K
Reaction Rate experiment: Potassium Permanganate and Hydrogen Peroxide
Replies
3
Views
3K

Hot Threads

Recent Insights

Back
Top