Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Indiabix, etc. - ChELE M2024 > Heat Transfer / Thermo > Flashcards

Heat Transfer / Thermo Flashcards

1
Q

another term for momentum diffusivity

A

kinematic viscosity, m^2/s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

heat transfer through physical contact

A

conduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

heat transfer due to movement of fluid (gas/ liquid)

A

convection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

heat transfer due to electromagnetic waves

A

radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Under the same temperature gradient across various metal plates of the same thickness, the heat conducted per unit of surface area will be largest across

A

copper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

If a man touches two metals which are kept together at room temperature, why would one metal feel colder than the other?

A

One has a high thermal conductivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The insulation ability of an insulator with the presence of water would

A

Decrease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

is the change in temperature of a gas when it undergoes isenthalpic expansion.

A

Joule Thomson Effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

__________ explains the equilibrium constant for any chemical reaction.

A

Law of mass action

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

If the vapour pressure at two
temperatures of a solid phase in equilibrium with its liquid phase are known, then the latent heat of fusion can be calculated by the

A

Clayperon-Claussius equation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Temperature scales with ratios that depend on ratios of heat transfer between a reversible heat engine and the reservoirs.

A

Absolute temperature scales

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Gibbs-Duhem equation relates composition in liquid phase and the __________ at constant temperature & pressure.

A

-fugacity
-partial pressure
-activity co-efficient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

“The rate at which a substance reacts is proportional to its active mass and the rate of a chemical reaction is proportional to the product of active masses of the reacting substances”. This is the

A

Law of Mass Action
(none of these and sagot)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The change in __________ is equal to the reversible work for compression in steady state flow process under isothermal condition.

A

Gibbs free energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

A nozzle is a device, which

A

increases kinetic energy and decreases pressure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

For any closed system formed from known amounts of prescribed chemical species, the equilibrium state is completely determined when any two independent variables are fixed.

A

Duhem’s theorem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Lee/Kesler correlation is only applicable for the following compound

A

non-polar and slightly polar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

It is a liquid that does not flow at all until a threshold shear stress is attained.

A

Bingham plastic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The work done in a free expansion process is

A

Zero

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Reaction conversion increases with an increase in temperature in the

A

Reversible endothermic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Potential flow is the flow of

A

Incompressible fluids with no shear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

With increase in molecular weight of the gas, the head developed by a centrifugal compressor will ___

A

decrease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Pressure drop is proportional to the 1st power of the velocity

A

Laminar flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Closed system that produce the maximum work?

A

Reversible cyclic process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How to calculate non reversible entropy?

A

Entropy is state function. S,rev = S,irrev

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Gibbs Free Energy
(Proponent, Equation, Definition)

A

Josiah Willard Gibbs
G=H-TS
Maximum work by system at P&T=k

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

miles to ft

A

1 mi = 5280 ft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

If a heat transfer equipment, dirt or scale may be accounted by introducing resistance called ______

A

fouling factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

thermal conductivity of steel, ka

A

45W/m-K

26 BTU/hr-ft-F

30
Q

The number of degrees of freedom for an azeotropic mixture in a two component vapour-liquid equilibria is/are

A zero
B one
C two
D three

A

zero

31
Q

What is the value of ln y (where y = activity co-efficient) for ideal gases ?

A Zero
B Unity
C Infinity
D Negative

A

Zero

32
Q

The number of degrees of freedom for an azeotropic mixture in a two component vapour-liquid equilibria is/are

A

one

33
Q

Any substance above its critical temperature exists as

A saturated vapour
B solid
C gas
D liquid

A

gas

34
Q

Which of the following decreases with increase in pressure ?

A Melting point of ice
B Melting point of wax
C Boiling point of liquids
D none of these

A

Melting point of ice

35
Q

(1) is the mathematical expression

A

co-efficient of thermal expansion.

36
Q

In case of steady flow compression polytropic process (PVn = constant), the work done on air is the lowest, when
A n = y = 1.4
B n = 0
C n = 1
D n = 1.66

A

n = 1

37
Q

A liquid under pressure greater than its vapour pressure for the temperature involved is called a __________ liquid.

A subcooled
B saturated
C non-solidifiable
D none of these

A

subcooled

38
Q

For a real gas, the chemical potential is given by
A RT dlnP
B RT dlnf
C R dlnf
D none of these

A

RT dlnf

39
Q

At absolute zero temperature, all substances have the same
A heat capacity
B crystalline structure
C entropy
D none of these

A

heat capacity

40
Q

Lowering of condenser temperature (keeping the evaporator temperature constant) in case of vapour compression refrigeration system results in

A increased COP.
B same COP.
C decreased COP.
D increased or decreased COP ; depending upon the type of refrigerant.

A

increased COP.

41
Q

Pick out the correct statement.

A If an insoluble gas is passed through a volatile liquid placed in a perfectly insulated container, the temperature of the liquid will increase.
B A process is irreversible as long as Δ S for the system is greater than zero.
C The mechanical work done by a system is always equal to P.dV.
D The heat of formation of a compound is defined as the heat of reaction leading to the formation of the compound from its reactants.

A

The heat of formation of a compound is defined as the heat of reaction leading to the formation of the compound from its reactants.

42
Q

Grams of butane (C4H10) formed by the liquefaction of 448 litres of the gas (measured at (STP) would be

A

A 580
B 640
C 1160
D data insufficient; can’t be computed

43
Q

The thermodynamic law, PVy = constant, is not applicable in case of
A ideal compression of air.
B free expansion of an ideal gas.
C adiabatic expansion of steam in a turbine.
D adiabatic compression of a perfect gas.

A

free expansion of an ideal gas.

44
Q

Mollier diagram is a plot of

A

entropy vs. enthalpy

45
Q

is the mathematical expression for

A

none of these

46
Q

The activity of an ideal gas is numerically __________ its pressure.

A

equal to

47
Q

Specific heat of a gas for a reversible adiabatic process is
A negative
B zero
C infinity
D none of these

A

zero

48
Q

When a gas in a vessel expands, its internal energy decreases. The process involved is
A reversible
B irreversible
C isothermal
D adiabatic

A

reversible

49
Q

A system is said to be isopiestic, if there is no __________ change.

A

pressure

50
Q

In a turbine, the fluid expands almost
A isothermally
B isobarically
C adiabatically
D none of these

A

adiabatically

51
Q

The unity of Planck’s constant ‘h’ in the equation, E = hv is

A

J*S

52
Q

Refrigeration capacity of a household refrigerator may be round about __________ tons.

0.15
1.5
4.5
6.5

A

0.15

53
Q
A
54
Q

An ideal gas is taken around the cycle ABCA as shown in P-V diagram below :The work done by the gas during the cycle is equal to

A 12 P1V1
B 6 P1 V1
C 3 P1V1
D P1 V1

A

3 P1V1

55
Q

In polytropic process (PVn = constant), if n = 1; it means a/an __________ process.

A

isothermal

56
Q

The melting point of paraffin wax (which contracts on solidification) __________ with pressure rise.

A

increases

57
Q

A solid metallic block weighing 5 kg has an initial temperature of 500°C. 40 kg of water initially at 25°C is contained in a perfectly insulated tank. The metallic block is brought into contact with water. Both of them come to equilibrium. Specific heat of block material is 0.4 kJ.kg^-1. K^-1. Ignoring the effect of expansion and contraction and also the heat capacity to tank, the total entropy change in kJ.kg^-1 , K^-1 is

A

0

58
Q

dW and dq are not the exact differential, because q and W are
A state functions
B path functions
C intensive properties
D extensive properties

A

path functions

59
Q

Activity co-efficient is a measure of the

A departure from ideal solution behaviour.
B departure of gas phase from idea] gas law.
C vapour pressure of liquid. D none of these.

A

departure from ideal solution behaviour.

60
Q
A
61
Q

While dissolving a gas into a liquid at a constant temperature, the ratio of the concentration of the gas in the solution phase and in the gaseous phase is

A

constant

62
Q

For an isothermal reversible compression of an ideal gas
A only ΔE = 0
B only ΔH =0
C ΔE = ΔH = 0
D dQ = dE

A

ΔE = ΔH = 0

63
Q

Melting of ice exemplifies a/an
A adiabatic process.
B endothermic reaction.
C exothermic reaction.
D process involving a chemical reaction.

A

endothermic reaction.

64
Q

Kopp’s rule is used to calculate the heat capacity of

A

solids

65
Q

__________ explains the equilibrium constant for any chemical reaction.

A

Law of Mass Action

66
Q

Pick out the wrong statement.

A A closed system does not permit exchange of mass with its surroundings but may permit exchange of energy.
B An open system permits exchange of both mass and energy with its surroundings.
C The term microstate is used to characterise an individual, whereas macro-state is used to designate a group of micro-states with common characteristics.
D none of the above.

A

none of the above.

67
Q

Requisites of a reversible process is that the

A system and surroundings pressure be equal.
B friction in the system should be absent.
C system and surroundings temperature be equal.
D none of these.

A

B friction in the system should be absent.

68
Q

The energy of activation of exothermic reaction is
A zero.
B negative.
C very large compared to that for en-dothermic reaction.
D not possible to predict.

A

D not possible to predict.

69
Q

Pick out the wrong statement.

A The chemical potential of a pure substance depends upon the temperature and pressure.
B The chemical potential of a component in a system is directly proportional to the escaping tendency of that component.
C The chemical potential of ith species (μi) in an ideal gas mixture approaches zero as the pressure or mole fraction (xi) tends to be zero at constant temperature.
D The chemical potential of species ‘i’ in the mixture (μi) is mathematically represented as, (1) , where, n, ni and nj respectively denote the total number of moles, moles of ith species and all mole numbers except ith species. ‘G’ is Gibbs molar free energy.

A

C The chemical potential of ith species (μi) in an ideal gas mixture approaches zero as the pressure or mole fraction (xi) tends to be zero at constant temperature.

70
Q

In the reaction; N2 + O2 (1) 2NO, increasing the pressure will result in
A shifting the equilibrium towards right,
B shifting the equilibrium towards left.
C no change in equilibrium condition.
D none of these.

A

no change in equilibrium condition.

71
Q

Joule-Thomson effect i.e., a throttling process is a constant __________ process.

A entropy
B temperature
C internal energy
D enthalpy

A

D enthalpy

72
Q

The number of degree of freedom for an azeotropic mixture of ethanol and water in vapour-liquid equilibrium, is A 3
B 1
C 2
D 0

A

Indiabix, etc. - ChELE M2024 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions