EASY
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What is E for system that does 500 cal of work on surrounding and 300 cal of heat is absorbed by the system?

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Important Questions on Thermodynamics

EASY
A system does 200 J of work and at the same time absorbs 150 J of heat. The magnitude of the change in internal energy is  ______J. (Nearest integer)
EASY
Which of the following can be considered as the definition/principle of energy?
MEDIUM
365 calorie heat is required to evaporate one gram water at 100C. If the work done by the system is 651.3 calorie, then the increase in internal energy per mole of water will be
MEDIUM
A piston filled with 0.04 mol of an ideal gas expands reversibly from 50.0 mL to 375 mL at a constant temperature of 3 7 . 0 C. As it does so, it absorbs 208 J of heat. The values of q and w for the process will be 
(R = 8.314 J/mol K) (ln7.5 = 2.01)
EASY
A gas undergoes change from state A to state B. In this process, the heat absorbed and work done by the gas is 5 J and 8 J, respectively. Now gas is brought back to A by another process during which 3 J of heat is evolved. In this reverse process of B to A.
MEDIUM
A system undergoes a process in which ΔU=+300 J while absorbing 400 J of heat energy and undergoing an expansion against 0.5 bar. What is the change in volume (in L) ?
HARD

The specific heat of a certain substance is 0.86 J g-1 K-1. Assuming ideal solution behavior, the energy required (in J) to heat 10 g of 1 molal of its aqueous solution from 300 K to 310 K is closest to :

[Given: molar mass of the substance =58 g mol-1; specific heat of water =4.2 J g-1 K-1]

EASY
If work done by the system is 300 Joule when 100 Cal, heat is supplied to it. The change in internal energy during the process is :-
MEDIUM
The molar enthalpy change for H2OlH2Og at 373 K and 1 atm is 40 kJ/mol . Assuming ideal behaviour, the internal energy change for vaporization of 1 mol of water at 373 K and 1 atm in kJ mol-1 is:
EASY
During compression of a spring the work done is 10 kJ and 2 kJ escaped to the surroundings as heat. The change in internal energy, ΔUinkJ is:
MEDIUM
When a gas is allowed to expand in a well-insulated container, against a constant external pressure of 5 atm, from an initial value of 10 L to a final volume of 15 L, find the change in the internal energy (ΔU) of the gas.
MEDIUM
A system absorbs 6 kJ of heat and does 1.5 kJ of work on its surroundings. The change in internal energy is _____.
EASY
When the temperature of 2 moles of an ideal gas is increased by 20°C at constant pressure, find the work involved in the process.
MEDIUM
A system gives out 30 J of heat and does 75 J of work. What is the internal energy change?
MEDIUM

2.2 g of nitrous oxide N2O gas is cooled at a constant pressure of 1 atm from 310 K to 270 K causing the compression of the gas from 217.1 mL to 167.75 mL. The change in internal energy of the process, U is '-x'J. The value of 'x' is _____.

[nearest integer]

(Given: atomic mass of N=14 g mol-1 and of O=16 g mol-1. Molar heat capacity of N2O is 100 JK-1 mol-1)

EASY
Which of the following equations represents the first law of thermodynamics under isobaric conditions?
EASY
Following figure shows two processes A and B  for a gas. If QA and QB are the amount of heat absorbed by the system in two cases, and UA and UB are changes in internal energies, respectively, then:
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EASY
The first law of thermodynamics for isothermal process is
HARD
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The above P-V diagram represents the thermodynamic cycle of an engine, operating with an ideal mono-atomic gas. The amount of heat, extracted from the source in a single cycle, is: