Question

is enthalpy , heat/thermal energy?

Answer 1

Enthalpy is a measure of internal energy, or how much energy is stored in a system

Answer 2

So, it can be released as heat/thermal energy, but it is not heat while it is stored.

Answer 3

Make sense?

Answer 4

so it can be potential enrgy as well as the energy it releases but t entahlpy is NOT the energy itself. example heat

Answer 5

and also in a calorimeter.... when the heat of your medium lets say water increases, water releases energy does that mean the temp of substance decreases?

so i know that when the temp of water increases water releases energy which transfers to the substance (exothermic for water and endothermic for substance undergoing chemical reaction) but wouldnt that make the temp of the SUBSTANCE decrease?

Answer 6

Ok, hold on a sec. When you have a calorimeter, when the temp of the water increases, the water is absorbing energy, not releasing.

Answer 7

And the energy it absorbs is coming from the substance, meaning that it loses energy due to its change in temp.

Answer 8

maybe ijust misunderstood my notes... ill type my notes out:

if temp of water increases, exothermic reaction occurs....

so that saying when water temp increase substance will lose energy not water..

Answer 9

Right, the temp of the water is increasing because the exothermic reaction released heat that the water absorbed.

Answer 10

so the temp of the substance IS the temp of the medium

Answer 11

Once they reach equilibrium, yes. But not until then.

Answer 12

The medium is the water.

Answer 13

oh wait i understand ok thanks, oh and back to my original question...

Answer 14

so it can be potential enrgy as well as the energy it releases but t entahlpy is NOT the energy itself. example heat

Answer 15

Right, enthalpy is stored (potential) energy, not heat

Answer 16

Stored in the bonds

Answer 17

OK thank you !!

Answer 18

You're very welcome!

Answer 19

* or surroundings to system

Answer 20

my first question i deleted so here it is:

for CALORIMETRY, can enthalpy or enthalpy change be defined as heat transfer from system to surroundings or surrounndings to system?


Sorry i know its alot but please im actually desperate :S

Answer 21

second question:

when system releases energy its gonna have low potential energy, and surroundings is gonna have high kinetic.
so could you also say that when the system releases energy would it have high kinetic energy, while the surrounding has low potential?

Answer 22

or in order to have the kinetic energy does the heat energy have to be absorbed and not released?

thus when system releases energy its gonna have low potential energy, and surroundings is gonna have high kinetic.
and not
so could you also say that when the system releases energy would it have high kinetic energy, while the surrounding has low potential?

Answer 23

@joannablackwelder