GATE MT topic:laws-thermodynamics PYQs & Answers — Page 4

Questions 31–40 of 69. Imported answers require independent review unless marked reviewed.

A spherical gas bubble of radius 0.01 mm is entrapped in molten steel held at 1773 K. If the pressure outside the bubble is 1.5 bar, the pressure inside the bubble is ______ bar (round off to 1 decimal place).

Given: 1 bar =

Pa and the surface tension of the steel at 1773 K is

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

What is the equilibrium

ratio for the given reaction at 1873 K? (round off to 2 decimal places)

Mo(s) + O

(g) ↔ MoO

(s)

Given:

;

and

for the reaction CO(g) + 0.5O

(g) ↔ CO

(g);

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

The partial molar enthalpy of Au in an Ag-Au melt containing 25 mol% Au at 1400 K is −8300 J·mol⁻¹. Assuming regular solution behavior, the activity of Au in the melt is ______ (round off to 3 decimal places).

Given:

J·K⁻¹·mol⁻¹

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Assuming that Dulong-Petit law is valid for a monoatomic solid, the ratio of heat capacities

at 500 K is ______ (round off to 3 decimals).

Given: molar volume = 7×10⁻⁶ m³·mol⁻¹,

isothermal compressibility = 8×10⁻¹² Pa⁻¹,

isobaric expansivity = 6×10⁻⁵ K⁻¹ and

J·K⁻¹·mol⁻¹.

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

The equilibrium microstructure of an alloy A-B consists of two phases α and β in the molar proportion 2:1. If the overall composition of the alloy is 70 mol% B and the composition of β is 90 mol% B, the composition of α is _____ (in mol% B) (round off to the nearest integer).

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Elements A and B have the same crystal structure. For a dilute solution of B in A, which one of the following is true?

(Given:

– Mixing enthalpy,

– Activity of B and

– Mole fraction of B)

Your answerChoose one option.

, then

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Melting point of Cu is 1358 K and its enthalpy of melting is 13400 J mol

. The value of free energy change (in J mol

) for liquid to solid transformation at 1058 K is: __________ (round off to nearest integer).

Assume:

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

The vacancy concentration in a crystal doubles upon increasing the temperature from 27 °C to 127 °C. The enthalpy (in kJ mol

) of vacancy formation is: ______ (round off to 2 decimal places). Given:

J mol

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Number of degrees of freedom for the following reacting system is: M (s) + CO₂ (g) = MO (s) + CO (g)

Your answerChoose one option.

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

The condition for getting the binary phase diagram of A-B (shown below) is:

Diagram for Metallurgical Engineering question 30

Given:

– Enthalpy of mixing of solid

– Enthalpy of mixing of liquid

Your answerChoose one option.

and

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

GATE MT topic:laws-thermodynamics PYQs

Question 47

Question 48

Question 53

Question 57

Question 65

Question 6

Question 17

Question 25

Question 29

Question 30