## closed vs isolated

Ekayana Sethi 2K
Posts: 47
Joined: Wed Nov 16, 2016 3:03 am
Been upvoted: 1 time

### closed vs isolated

Are the pressures and volumes constant in a closed and isolated system?

Rachel Lu_dis1H
Posts: 66
Joined: Fri Sep 29, 2017 7:06 am
Been upvoted: 1 time

### Re: closed vs isolated

I don't think they are unless it says otherwise. I do know that if it's a bomb calorimeter volume stays constant

SitharaMenon2B
Posts: 50
Joined: Thu Jul 27, 2017 3:01 am

### Re: closed vs isolated

No, specifying the system as closed or isolated doesn't mean that the pressure or volume are constant.

Justin Folk 3I
Posts: 43
Joined: Wed Sep 21, 2016 2:56 pm

### Re: closed vs isolated

No, closed is just where matter can't escape. isolated is where neither matter nor internal energy can escape

Michelle Lee 2E
Posts: 64
Joined: Thu Jul 27, 2017 3:01 am

### Re: closed vs isolated

The text has to say if it is under constant pressure or volume. I don't think assuming is good enough.
I also have a question.
When the text says "ideal", does that mean constant pressure and volume because ideal would be 1 atm and 1M?

Xin He 2L
Posts: 38
Joined: Fri Sep 29, 2017 7:05 am

### Re: closed vs isolated

You don't want to assume anything, but if the question says that the reaction happens in a bomb calorimeter, you can assume it's constant volume.

Sarah 2F
Posts: 33
Joined: Fri Sep 29, 2017 7:06 am

### Re: closed vs isolated

You can only assume that if the problem says so.

Alex Nechaev 1I
Posts: 50
Joined: Fri Sep 29, 2017 7:04 am

### Re: closed vs isolated

Knowing whether a system is closed or isolated only tells you whether it can exchange energy with its surroundings or not. Don't assume that pressures and volumes are constant unless the problem specifically states that they are.

Annie Lieu-1H
Posts: 68
Joined: Fri Sep 29, 2017 7:04 am
Been upvoted: 1 time

### Re: closed vs isolated

No, unless the problem specifies. When given just "closed" or "isolated" that deals with energy exchange (or lack thereof).

804899546
Posts: 51
Joined: Sat Jul 22, 2017 3:00 am

### Re: closed vs isolated

An example would be the expansion of a balloon. Say the pressure outside the balloon decreased, the volume of the balloon would increase as it expanded. However, it is still a closed system because the balloon never actually lost any matter, it just reacted to outside conditions.

Justin Folk 3I
Posts: 43
Joined: Wed Sep 21, 2016 2:56 pm

### Re: closed vs isolated

Does heat transfer happen when the balloon loses air?

Rachel N 1I
Posts: 48
Joined: Thu Jul 27, 2017 3:00 am

### Re: closed vs isolated

Yes, heat transfer does happens because they system is doing work and losing energy. This energy is replaced by heat flow, q, into the system.