What Are the Units of Mass and Heat Quantity in Thermochemistry?

  • Thread starter Thread starter ph_lover3294
  • Start date Start date
  • Tags Tags
    Heat Law Mass
AI Thread Summary
The discussion revolves around the units of mass and heat quantity in thermochemistry, specifically in the context of the equation for calculating heat transfer. Participants clarify that milliliters and liters are units of volume, not mass, and emphasize the need to use appropriate units for mass, temperature, and specific heat. A calculation example is provided, where the liberated heat from mixing a diluted base and acid is calculated to be approximately 1.298 kJ, contrasting with an incorrect book answer of 1295.8 kJ. The correct calculation is confirmed to be 1298 Joules or 1.298 kJ, highlighting the importance of unit accuracy in thermochemical calculations. The discussion underscores the significance of understanding the correct units in thermochemical equations.
ph_lover3294
Messages
9
Reaction score
0
hi for u all

i want to ask a question in a thermochemistry about the law of

quantity of heat = mass . specefic heat . change in temp

firstly . i want to know the units of (mass ) and (heat quantity) in this law
(gm , ml , liter)...(joules,kj)
Q: on adding 50 ml of diluted base on 50 ml of diluted acid in isolated cal. the temp. of the solution rises from 18.2 to 21.3 degree
calculate the liberated heat

thanks ...i wish u answer me quickly ...

bye
 
Physics news on Phys.org


ph_lover3294 said:
i want to know the units of (mass ) and (heat quantity) in this law (gm , ml , liter)...(joules,kj)

ml and liter are not units of mass, but units of volume.

Exact units used don't matter. You need to use units of mass, units of temperature and specific heat that is expressed using these units and units of energy that you want your answer to be in.
 
Last edited:


thank u for your answer

but i want to know the answer of the above question
please

i answered it ...

liberated heat=100 x 4.18 x (21.3-18.2)=1295.8 j =1.2958 kj
but the answer of the book was ..1295.8 kj
so i don't know the right answer

thanks
 
Last edited:


123 cBTU.
 


i m sorry ..i didn't understand your answer ..
 


You have edited your post while I was composing mine, I have not seen your answer.

1298 Joules or 1.298 kJ it is (assuming data you have listed is correct). 1298 kJ is wrong.
 
I don't get how to argue it. i can prove: evolution is the ability to adapt, whether it's progression or regression from some point of view, so if evolution is not constant then animal generations couldn`t stay alive for a big amount of time because when climate is changing this generations die. but they dont. so evolution is constant. but its not an argument, right? how to fing arguments when i only prove it.. analytically, i guess it called that (this is indirectly related to biology, im...
Back
Top