Answer to Question #65758 in Physical Chemistry for muhd

Question

Question 1 : The zeroth law of thermodynamics is based on the concept of
entropy
Conservation of energy
absolute zero temperature
thermodynamic equivalence
Question 2 : Which of these does not depict thermodynamics?
Rate of reaction
Performance of car engine
Melting of ice
Boiling water for coffee
Question 3 : Which of these is not an extensive property of a system?
Mass
Energy
Density
Volume
Question 4 : Which of the following statements about enthalpy is incorrect?

Δ
H
ΔH is the enthalpy change at constant pressure
Reactions which absorb heat have a positive DH
Enthalpy and internal energy of a system are always identical
enthalpy is a state function
Question 5 : The first law of thermodynamics deals with
conservation of energy
entropy
thermodynamic equivalence
absolute zero temperature.

Answer 1

Question 1: Zero law of thermodynamics - a theorem which is formulated as follows: if two systems are in a state of thermal equilibrium with a third system, they are in a state of thermal equilibrium with each other. Obviously, the state of thermal equilibrium is nothing but equality temperatures. So the correct answer: thermodynamic equivalence.

Question 2: Thermodynamics - the branch of physics that studies the most general properties of macroscopic systems and processes of energy transfer and transformation in such systems. So the
correct answer: rate of reaction.

Question 3: Density – intensive property of system. So the correct answer: density.

Question 4: Enthalpy and internal energy of the system are not always identical, only in certain cases. So the correct answer: enthalpy and internal energy of a system are always identical.

Question 5: The first law of thermodynamics - energy of an isolated system keeps a constant with all the changes taking place in the system, or what is the same, the energy does not arise out of nothing, and can not turn into nothing. So the correct answer: conservation of energy.

Answer: Question 1: thermodynamic equivalence;
Question 2: rate of reaction;
Question 3: density;
Question 4: enthalpy and internal energy of a system are always identical;
Question 5: conservation of energy.