Thermodynamics - lecture 1

Question 1

What is the first law of thermodynamics ?

Answer 1

the energy is neither created nor destroyed but just transformed from one kind to another.

Question 2

What is work?

Answer 2

Work is the transfer of energy that can cause motion against an opposing force.

Question 3

Describe what happens in a negative change in temperature.

Answer 3

this means the the heat is transferred out of the substance and then q is negative. this process is exothermic.

Question 4

Describe what happens when there is a positive change in temperature.

Answer 4

This means the temperature is transferred into the substance and q is positive. this process is endothermic.

Question 5

What is enthalpy ?

Answer 5

Enthalpy can be a state property as its value depends on the current state of the systems so its temperature for instance is independent of how the system was prepared in that state.

Question 6

What is the standard state ?

Answer 6

The standard state of a substances at a specified temperature (e.g 298 K) it is pure from at a pressure of 1 bar.