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!

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 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 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)

What are the sign convention of work done on the system and work done by the system?

If energy enters the system, its sign is positive. If energy leaves the system, its sign is negative. If work is done on the system, its sign is positive. If work is done by the system, its sign is negative.

What is the sign convention when work is done on the system by the surrounding?

When work is done on the system by the surroundings, work has positive value (i.e., +W).

Why is work done negative thermodynamics?

The negative sign associated with PV work done indicates that the system loses energy. If the volume increases at constant pressure (ΔV > 0), the work done by the system is negative, indicating that a system has lost energy by performing work on its surroundings.

What symbols signs are used for work done on the system and work done by the system?

If energy leaves the system, its sign is negative. If work is done on the system, its sign is positive. If work is done by the system, its sign is negative.

What is the sign convention when work done on the system by the surrounding?

What are the sign conventions for work and heat?

Sign Conventions for Heat and Work

• The signs of ‘w’ and ‘q’ are related to the internal energy change. When ‘w’ or ‘q’ is positive, it means that energy has been supplied to the system as work or as heat.
• Heat evolved by the system= q negative.
• Work done by the system= w negative.