"Heat added to a system at lower temperature causes greater randomness than when the same quantity of heat is added to it at higher temperature. "

this can mean 2 things

1. heating a colder object causes more randomness or

2. supplying same amount of heat slowly causes more randomness

I think the 2nd one because ∆S = qrev/T

Edited September 7Sep 7 by HbWhi5F

1 hour ago, HbWhi5F said:

"Heat added to a system at lower temperature causes greater randomness than when the same quantity of heat is added to it at higher temperature. "

this can mean 2 things

1. heating a colder object causes more randomness or

2. supplying same amount of heat slowly causes more randomness

I think the 2nd one because ∆S = qrev/T

This needs care. What are you quoting from?

I see his school work has moved to Thermodynamics, after Chemical Bonding.

Show us YOUR thinking/reasoning so far.
( hint; look at the effect of differing T, when the same amount of heat, Q, is added, in your equation for change in entropy, S )

Edited September 7Sep 7 by MigL

2 hours ago, HbWhi5F said:

"Heat added to a system at lower temperature causes greater randomness than when the same quantity of heat is added to it at higher temperature. "

A quote implies you read this somewhere. You should reveal where.

5 hours ago, HbWhi5F said:

"Heat added to a system at lower temperature causes greater randomness than when the same quantity of heat is added to it at higher temperature. "

Think 'diversity' rather than 'randomness'.

A fast moving car entering a parking lot creates a greater overall diversity than a fast moving car entering a freeway.

5 hours ago, sethoflagos said:

Think 'diversity' rather than 'randomness'.

A fast moving car entering a parking lot creates a greater overall diversity than a fast moving car entering a freeway.

I don't think analogy is the way to go with this kind of thing, we are already discussing equations and terms.

Edited September 8Sep 8 by pinball1970
Typo

@swansont This is from NCERT Class 11 Chapter 5

@MigL Studying

1 hour ago, HbWhi5F said:

@swansont This is from NCERT Class 11 Chapter 5

@MigL Studying

Ah, thanks, so this is the Indian government school material that goes up to class 12 in the final year of secondary education. So you are in your penultimate year of secondary school then. That is useful background to your series of questions.

13 hours ago, HbWhi5F said:

"Heat added to a system at lower temperature causes greater randomness than when the same quantity of heat is added to it at higher temperature. "

this can mean 2 things

1. heating a colder object causes more randomness or

2. supplying same amount of heat slowly causes more randomness

I think the 2nd one because ∆S = qrev/T

It's not to do with the speed at which heat is supplied though. There is no time dependence in dQ(rev)/T= dS.

So I would say it is closer to 1 than 2. Transferring heat at a lower temperature results in it being distributed in more different ways within the substance.

11 hours ago, pinball1970 said:

I don't think analogy is the way to go with this kind of thing, we are already discussing equations and terms.

Then, with all due respect, perhaps you don't understand why the OP phrased the question the way he did.

34 minutes ago, sethoflagos said:

Then, with all due respect, perhaps you don't understand why the OP phrased the question the way he did.

Yes I quite like your analogy, though I think it needs a fair bit of explanation for our 6th form scholar. Entropy, or rather entropy change, which is what we are talking about in this instance, is notoriously tricky to visualise at the molecular level.

Your point, I presume, is that the increase in "diversity", when heat is to supplied to molecules that are mostly initially in the ground state, is greater than if they are already busy cascading among numerous thermally excited states before the extra heat is added.

1 minute ago, exchemist said:

Yes I quite like your analogy, though I think it needs a fair bit of explanation for our 6th form scholar. Entropy, or rather entropy change, which is what we are talking about in this instance, is notoriously tricky to visualise at the molecular level.

Largely because the misleading term 'random' keeps being used.

7 minutes ago, exchemist said:

Your point, I presume, is that the increase in "diversity", when heat is to supplied to molecules that are mostly initially in the ground state, is greater than if they are already busy cascading among numerous thermally excited states before the extra heat is added.

It's about how significant a change of state a given Q causes at different temperatures.

The initial state of a parking lot may be summarized as: n vehicles, all stationary.

That of a given length of freeway may be: n vehicles travelling with an average velocity of 60 mph with a standard deviation of 10 mph. (a bit longer because it has more entropy/diversity).

Add an extra vehicle travelling at 65 mph to each. How much do the descriptions of state need to be changed?

'More of the same' has little impact on entropy/diversity. Extending the tail end of a distribution has a lot more.

1 hour ago, sethoflagos said:

Then, with all due respect, perhaps you don't understand why the OP phrased the question the way he did.

Fair enough +1

13 hours ago, HbWhi5F said:

@swansont This is from NCERT Class 11 Chapter 5

@MigL Studying

So it’s https://ncert.nic.in/textbook/pdf/kech105.pdf page 159 (I’d quote but the text is copy-restricted)

You should read the part before that to add some context to it, where it talks about the randomness of molecular motion.

Unfortunately the explanation isn’t quite as rigorous as it should be, but temperature is related to the average KE of the random motion of the molecules, and KE = 1/2 mv^2

So adding a set amount of heat does not increase the motion in a linear way. i.e. if you double the temperature, v does not double. The motion is affected more at low T, so the change in randomness is bigger at low T, for a set amount if heat added.

1 hour ago, sethoflagos said:

Largely because the misleading term 'random' keeps being used.

It's about how significant a change of state a given Q causes at different temperatures.

The initial state of a parking lot may be summarized as: n vehicles, all stationary.

That of a given length of freeway may be: n vehicles travelling with an average velocity of 60 mph with a standard deviation of 10 mph. (a bit longer because it has more entropy/diversity).

Add an extra vehicle travelling at 65 mph to each. How much do the descriptions of state need to be changed?

'More of the same' has little impact on entropy/diversity. Extending the tail end of a distribution has a lot more.

Yes, more or less what I was also trying to say. Like you, I'm chary of the word "random" in this context. It's more a matter of dispersion (of energy), I think.

Random is being used because it’s in the source text (which I noted lacks rigor) and answers are being provided in that context.

3 hours ago, sethoflagos said:

Then, with all due respect, perhaps you don't understand why the OP phrased the question the way he did.

Which is why I wanted the source. Context is almost always important when there’s confusion surrounding a short snippet of quoted text.