HARD
Earn 100

According to IUPAC conventions work done on the surroundings is :

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Important Questions on Chemical Thermodynamics

EASY

The quantity of heat (in J) required to raise the temperature of 1.0 kg of ethanol from 293.45 K to the boiling point and then change the liquid to vapor at that temperature is closest to [Given, boiling point of ethanol 351.45 K. Specific heat capacity of liquid ethanol 2.44 J g-1 K-1. Latent heat of vaporisation of ethanol 855 Jg-1 ]

 

MEDIUM
Two moles of helium gas is mixed with three moles of hydrogen molecules (taken to be rigid). What is the molar specific heat of mixture at constant volume? R=8.3 J/mol K
EASY
At constant pressure, the heat of formation of a compound is not dependent on temperature, when
EASY
The difference between C¯p and C¯V is C¯p and C¯V signify molar quantities]
MEDIUM
A gas is allowed to expand in a well-insulated container against a constant external pressure of 2.5 atm from an initial volume of 2.50 L to a final volume of 4.50 L. The change in internal energy ΔU of the gas in joules will be
EASY
A gas can expand from 100 mL to 250 mL under a constant pressure of 2 atm. The work done by gas is
EASY
For one mole of an ideal gas, which of these statements must be true?
(a) Internal energy (U) and enthalpy (H) each depends on temperature.
(b) Compressibility factor Z is not equal to 1
(c) CP, m CV, m=R
(d) dU=CvdT for any process
MEDIUM
A piece of metal weighing 100 g is heated to 80°C and dropped into 1 kg of cold water in an insulated container at 15°C. If the final temperature of the water in the container is 15.69°C, the specific heat of the metal in J/g°C. is
MEDIUM
At constant volume, 4 mol of an ideal gas when heated from 300K to 500K changes its internal energy by 5000J. The molar heat capacity at constant volume is ________
MEDIUM
5 moles of an ideal gas at 100 K are allowed to undergo reversible compression till its temperature becomes 200 K. If CV=28 J K-1, calculate U and pV for the process. (R=8.0 J K-1 mol-1)
EASY
Calculation the maximum work done in expanding 16 gof oxygen at 300 K and occupying a volume of 5 dm3 isothermally until volume becomes 25 dm3.
MEDIUM
X g of ice at 0oC is added to 340g of water at 20oC . The final temperature of the resultant mixture is 5oC . The value of X (in g) is closest to

[Heat of fusion of ice =333 J/g ; Specific heat of water =4.184 J/g.K ]
MEDIUM
What will be the heat change at constant volume fo the reaction whose heat change at constant pressure is -560 kcal at 27°C ? The reaction is: C8H16+12O28CO2+8H2O (Given R=2calmol-1 K-1
HARD
A thermally insulated rigid container of 1 L volume contains a diatomic ideal gas at room temperature. A small paddle installed inside the container is rotated from the outside, such that the pressure rises by 105 Pa. The change in internal energy is close to
MEDIUM

200 mL of 0.2 M HCl is mixed with 300 mL of 0.1 M NaOH. The molar heat of neutralization of this reaction is -57.1 kJ. The increase in temperature in C of the system on mixing is x×10-2. The value of x is (Nearest integer)

[Given: Specific heat of water =4.18 J g-1 K-1 

Density of water=1.00 g cm-3]

(Assume no volume change on mixing)

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
An ideal gas is allowed to expand from 1 L to 10 L against a constant external pressure of 1 bar. The work done in kJ is:
MEDIUM
For the isothermal reversible expansion of an ideal gas
EASY
Calculate the work done during compression of 2 mol of an ideal gas from a volume of 1m3 to 10 dm3 at 300 K against a pressure of 100 kPa.