English

Answer the following in one or two sentences. State the first law of thermodynamics. - Chemistry

Advertisements
Advertisements

Question

Answer the following in one or two sentences.

State the first law of thermodynamics.

One Line Answer

Solution

According to the first law of thermodynamics, “the total energy of a system and surroundings remains constant when the system changes from an initial state to final state.”

shaalaa.com
First Law of Thermodynamics
  Is there an error in this question or solution?
Chapter 4: Chemical Thermodynamics - Exercises [Page 87]

APPEARS IN

Balbharati Chemistry [English] 12 Standard HSC
Chapter 4 Chemical Thermodynamics
Exercises | Q 2.2 | Page 87
SCERT Maharashtra Physics [English] 12 Standard HSC
Chapter 4 Thermodynamics
Very Short Answer | Q 11
SCERT Maharashtra Physics [English] 12 Standard HSC
Chapter 4 Thermodynamics
Long Answer | Q 1.1
Samacheer Kalvi Chemistry - Volume 1 and 2 [English] Class 11 TN Board
Chapter 7 Thermodynamics
Evaluation | Q II. 1. | Page 224
Samacheer Kalvi Physics - Volume 1 and 2 [English] Class 11 TN Board
Chapter 8 Heat and Thermodynamics
Evaluation | Q II. 24. | Page 158

RELATED QUESTIONS

Write the mathematical expression of the First Law of Thermodynamics for the Isobaric process.


The first law of thermodynamics is a statement of ____________ .


A system can be taken from the initial state p1, V1 to the final state p2, V2 by two different methods. Let ∆Q and ∆W represent the heat given to the system and the work done by the system. Which of the following must be the same in both the methods?


Calculate the change in internal energy of a gas kept in a rigid container when 100 J of heat is supplied to it.


The pressure of a gas changes linearly with volume from 10 kPa, 200 cc to 50 kPa, 50 cc. (a) Calculate the work done by the gas. (b) If no heat is supplied or extracted from the gas, what is the change in the internal energy of the gas?


When a system is taken through the process abc shown in figure, 80 J of heat is absorbed by the system and 30 J of work is done by it. If the system does 10 J of work during the process adc, how much heat flows into it during the process?


Calculate the heat absorbed by a system in going through the cyclic process shown in figure.


The internal energy of a gas is given by U = 1.5 pV. It expands from 100 cm3 to 200 cm3against a constant pressure of 1.0 × 105 Pa. Calculate the heat absorbed by the gas in the process.


A gas is enclosed in a cylindrical vessel fitted with a frictionless piston. The gas is slowly heated for some time. During the process, 10 J of heat is supplied and the piston is found to move out 10 cm. Find the increase in the internal energy of the gas. The area of cross section of the cylinder = 4 cm2 and the atmospheric pressure = 100 kPa.


Consider the cyclic process ABCA, shown in figure, performed on a sample of 2.0 mol of an ideal gas. A total of 1200 J of heat is withdrawn from the sample in the process. Find the work done by the gas during the part BC.


Calculate the increase in the internal energy of 10 g of water when it is heated from 0°C to 100°C and converted into steam at 100 kPa. The density of steam = 0.6 kg m−3. Specific heat capacity of water = 4200 J kg−1 °C−1 and the latent heat of vaporization of water = 2.25 × 10 6J kg−1.


Choose the correct option.

Which of the following is an example of the first law of thermodynamics?


A solar cooker and a pressure cooker both are used to cook food. Treating them as thermodynamic systems, discuss the similarities and differences between them.


A resistor held in running water carries electric current. Treat the resistor as the system

  1. Does heat flow into the resistor?
  2. Is there a flow of heat into the water?
  3. Is any work done?
  4. Assuming the state of resistance to remain unchanged, apply the first law of thermodynamics to this process.

For an Isothermal process


For an Isochoric process


Define an isolated system.


10 kg of four different gases (Cl2, CH4, O2, N2) expand isothermally and reversibly from 20 atm to 10 atm. The order of amount of work will be ____________.


Which of the following are TRUE for a reversible isothermal process?

(i) ∆U = 0

(ii) ∆H = 0

(iii) Q = W

(iv) ∆T = 0


When heat energy of 2000 joules is supplied to a gas at constant pressure 2.1 x 105 N/m2, there is an increase in its volume equal to 2.5 x 10-3 m3. The increase in internal energy of the gas in joules is ____________.


"The mass and energy both are conserved in an isolated system", is the statement of ______.


A gas performs 0.320 kJ work on surrounding and absorbs 120 J of heat from the surrounding. Hence, change in internal energy is ______.


Based on first law of thermodynamics which of the following is correct.


In a given process for an ideal gas, dW = 0 and dQ < 0. Then for the gas ____________.


120 J of heat is added to a gaseous system, whose internal energy change is 60 J, then the amount of external work done is ____________.


For a particular reaction, the system absorbs 8 kJ of heat and does 2.5 kJ of work on its surrounding. What will be the change in internal energy of the system?


Calculate the amount of work done during isothermal expansion of a gas from a volume of 4 dm3 to 6 dm3 against a constant external pressure of 3 atmosphere?


If an average person jogs, hse produces 14.5 × 103 cal/min. This is removed by the evaporation of sweat. The amount of sweat evaporated per minute (assuming 1 kg requires 580 × 103 cal for evaparation) is ______.


An ideal gas undergoes cyclic process ABCDA as shown in given P-V diagram (figure). The amount of work done by the gas is ______.


Consider a cycle followed by an engine (Figure)

1 to 2 is isothermal
2 to 3 is adiabatic
3 to 1 is adiabatic


Such a process does not exist because ______.

  1. heat is completely converted to mechanical energy in such a process, which is not possible.
  2. mechanical energy is completely converted to heat in this process, which is not possible.
  3. curves representing two adiabatic processes don’t intersect.
  4. curves representing an adiabatic process and an isothermal process don’t intersect.

A system goes from P to Q by two different paths in the P-V diagram as shown in figure. Heat given to the system in path 1 is 1000 J. The work done by the system along path 1 is more than path 2 by 100 J. What is the heat exchanged by the system in path 2?


Air pressure in a car tyre increases during driving. Explain.


A cycle followed by an engine (made of one mole of an ideal gas in a cylinder with a piston) is shown in figure. Find heat exchanged by the engine, with the surroundings for each section of the cycle. (Cv = (3/2)R)

  1. AB : constant volume
  2. BC : constant pressure
  3. CD : adiabatic
  4. DA : constant pressure

The amount of heat needed to raise the temperature of 4 moles of a rigid diatomic gas from 0°C to 50°C when no work is done is ______.

(R is the universal gas constant.)


In the reported figure, heat energy absorbed by a system in going through a cyclic process is ______ πJ.


An electric appliance supplies 6000 J/min heat to the system. If the system delivers a power of 90 W. How long it would take to increase the internal energy by 2.5 × 103 J?


A system is taken through a cyclic process represented by a circle as shown. The heat absorbed by the system is ______.

 


200g water is heated from 40°C to 60°C. Ignoring the slight expansion of water, the change in its internal energy is close to ______.

(Given specific heat of water = 4184 J/kgK)


One mole of an ideal gas is allowed to expand reversibly and adiabatically from a temperature of 27°C. If the work done during the process is 3 kJ, the final temperature will be equal to ______.

(Cv = 20 JK−1)


Which among the following equations represents the first law of thermodynamics under isobaric conditions?


What work will be done, when 3 moles of an ideal gas are compressed to half the initial volume at a constant temperature of 300 K?


An ideal gas having pressure p, volume V and temperature T undergoes a thermodynamic process in which dW = 0 and dQ < 0. Then, for the gas ______.


A given system undergoes a change in which the work done by the system equals the decrease in its internal energy. The system must have undergone an ______.


Derive an expression for the work done during an isothermal process.


104 J of work is done on a certain volume of a gas. If the gas releases 125 kJ of heat, calculate the change in internal energy of the gas.


In an adiabatic process, ______.


What is true for an adiabatic process?


In an adiabatic process, W = ______.


For an isothermal and reversible expansion of 0.5 mol of an ideal gas Wmax is - 3.918 kJ. The value of ΔU is ______.


Using the first law of thermodynamics, show that for an ideal gas, the difference between the molar specific heat capacities at constant pressure and at constant volume is equal to the molar gas constant R.


In an adiabatic expansion of 2 moles of a gas, the initial pressure was 1.013 × 105 Pa, the initial volume was 22.4 L, the final pressure was 3.191 × 104 Pa and the final volume was 44.8 L. Find the work done by the gas on its surroundings. Taken `γ = 5/3`.


Show that the heat absorbed at constant pressure is equal to the change in enthalpy of the system.


Define isochoric process


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×