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Flashcards in Laws Of Thermodynamics. Deck (11):
1

What is molar heat capacity ?

Molar heat capacity is the heat required to raise the temperature of 1 mole of any substance by 1 C or 1 K.
It's denoted by C.

2

What is the formula of molar heat capacity ?

Q= nC(T'-T).
Molar heat capacity of liquids and solids is almost constant whereas it varies in gases.

3

What is denoted by Cv and Cp?

Cp is molar heat capacity due to isobaric process and Cv is molar heat capacity due to isochoric process.

4

What is the first law of thermodynamics ?

Q= ΔU + W.
It's the law of conservation of energy.

5

How to find work done using the first law of thermodynamics ?

W= p(Vf-Vi)=pΔV.
Is p is constant it means the process is adiabatic.
Work done can also be obtained by tea under p-V diagram with projection on V axis.

6

In the first law of thermodynamics , what can you say about the sign of work done in various scenarios in p vs V graph?

W=+ve as volume increases.
W=-ve as volume decreased.
W=0 if volume is constant.
W=+ve as cyclic process is clockwise with p on y axis
W=-ve as cyclic process is anti-clockwise with p on y axis.

7

Using the first law of thermodynamics, what is the formula of change is internal energy ΔU?

ΔU= n Cv ΔT. If either three terms are unknown then we can calculate ΔU by ΔU=Q-W.

8

Using the first law of thermodynamics , what is the formula for heat exchange Q?

Q= n C ΔT. If all the three quantities are unknown then, calculate Q=ΔU+W.

9

What can you say about isobaric process in term of x and slope ?

In isobaric process, x=0, therefore slope= 0.

10

What can you say about isothermal process in terms of x and slope ?

In isothermal process , x=1 and therefore slope = p/v.

11

What can you say about adiabatic process in terms of x and slope ?

x=γ and slope =-γ(p/V)