Advertisements
Advertisements
प्रश्न
Why work done in vacuum is zero?
Advertisements
उत्तर
A free expansion means expansion against zero opposing force. Such expansion occurs in a vacuum. When the gas expands in a vacuum, there is no opposing force, that is, Pext = 0. The work done by a system during such expansion is W = – Pext ∆V = 0.
Thus, work done in a vacuum is zero.
संबंधित प्रश्न
Answer the following in one or two sentences.
What is enthalpy of fusion?
Answer in brief.
What is the enthalpy of atomization? Give an example.
Define the Enthalpy of sublimation.
Define the Enthalpy of vaporization.
The enthalpy change for the reaction; \[\ce{Na_{(s)} -> Na_{(l)}}\] is called enthalpy of ____________.
The enthalpy change for the transition of liquid water to steam, ∆vapH = 37.3 kJ mol−1 at 373 K. The entropy change for the process is ____________.
The enthalpy change for the chemical reaction \[\ce{H2O_{(s)} -> H2O_{(l)}}\] is called enthalpy of ______.
Define the enthalpy of freezing.
How does entropy change in the following process? Explain.
Condensation of vapour
Enthalpy of fusion of ice at 0°C and 1 atmosphere is 6.01 kJ mol - 1 and enthalpy of evaporation of water at 0°C and 1 atmosphere is 45.07 kJ mo1 - 1. Calculate the enthalpy of sublimation of one mole of ice at 0°C and 1 atmosphere. Write the equation for the same.
Calculate the time required to deposit 2.4 g of \[\ce{Cu}\], when 2.03 A of current passed through \[\ce{CuSO4}\], solution. (At. mass of \[\ce{Cu}\] = 63.5 g mol−1)
Calculate the enthalpy of vaporisation of ethanol if 11.5 g of ethanol is completely vaporised by supplying 11.8 kJ of heat.
Which of the following statements is true for the given reaction?
\[\ce{Na(s) -> Na(g); \triangle H^Θ = 108.4 kJ}\] mol−1
