Table of Contents
- 1 Why is sign convention in thermodynamics different from physics and chemistry?
- 2 What is the sign convention for thermodynamics in physics?
- 3 What are the difference between the concept of Q and W in chemistry and physics?
- 4 What is the meaning of convention in physics?
- 5 Why do we have different sign conventions in physics and chemistry?
- 6 How are sign conventions different in both subjects?
Why is sign convention in thermodynamics different from physics and chemistry?
Fundamentally, thermodynamics in physics and chemistry is the same. The only difference is the notation of work in both, with work done by the system taken as positive in physics, and work done on the system taken as positive in chemistry. So, this is the distinction between the thermodynamics of physics and chemistry!
What is the sign convention for thermodynamics in physics?
Heat absorbed by the system = q+ (positive) Heat evolved by the system = q− (negative) Work done on the system = w+ (positive) Work done by the system = w− (negative)
Why is work done different in chemistry and physics?
The difference is only due to the different sign convention in Physics and Chemistry. In Chemistry, work done on the system is positive and in Physics, work done by the system. W is negative means system did work and W is positive means system has work done on it.
Why work done by the system is positive in physics and negative in chemistry?
Thus we define work as being positive when the system does work on the surroundings (energy leaves the system). If work is done on the system (energy added to the system), the work is negative.
What are the difference between the concept of Q and W in chemistry and physics?
Q is the net heat transferred into the system—that is, Q is the sum of all heat transfer into and out of the system. W is the net work done by the system—that is, W is the sum of all work done on or by the system.
What is the meaning of convention in physics?
In physics, a sign convention is a choice of the physical significance of signs (plus or minus) for a set of quantities, in a case where the choice of sign is arbitrary. In general, a sign convention is a special case of a choice of coordinate system for the case of one dimension.
What is meant by sign convention?
What are the differences between an open and closed system in regards to the flow of energy and matter?
An open system can exchange both energy and matter with its surroundings. The stovetop example would be an open system, because heat and water vapor can be lost to the air. A closed system, on the other hand, can exchange only energy with its surroundings, not matter.
Why do we have different sign conventions in physics and chemistry?
The reason being the sign convention is different in both the cases. In physics we take work done by the system as positive and in chemistry work done on the system. I realize that this does not cause any change in the actual law of nature but I just want to know why we have different sign conventions. Wouldn’t just one convention make life easier?
How are sign conventions different in both subjects?
Sign convention are different in both subjects. Sign conventions are different because both the subjects focus on different concept in the process. Fundamentals of the process are same but due to difference in concept to be focused, they show variation in calculation.
Why work done is positive in physics and negative in chemistry?
That’s why, In physics, work done by the system is positive because change in energy (due to the work done) of the surroundings is positive ! (Energy is released from the system to the surroundings) Whereas In chemistry, work done by the system is negative because the system loses some amount of energy to do work !
What is the difference between the thermodynamics of physics and chemistry?
The reason for this distinction can be that in physics, we are concerned with the study of the system and what it can do for us, whereas in chemistry, we are concerned with what we can do on the system to affect some kind of change in it. So, this is the distinction between the thermodynamics of physics and chemistry!