For the irreversible reaction, Ca+ 2C = Ca C2 , Δ H°298 = – 60000 J . mole-1 . If a system initially containing 2 moles of calcium, 3 moles of carbon and 1 mole of calcium carbide is allowed to react to completion, the heat evolved at 298 K will be__________________?
(A) 30,000 J
(B) 60,000 J
(C) 90,000 J
(D) 2,40,000 J
Hardening of steel is not possible, unless it is heated _________________ critical point ?
(A) Above the highest
(B) Above the lowest
(C) Between the first & second
(D) Between the second & third
Strain hardening effect in metals subjected to cold working is due to the _______________ mechanism?
(A) Slip
(B) Fracture
(C) Winning
(D) Dislocation
Atomic _________________ of an element is a whole number ?
(A) Weight
(B) Number
(C) Volume
(D) Radius
Which of the following heat treatment processes is usually applied to castings ?
(A) Tempering
(B) Annealing
(C) Normalising
(D) Carburising
A material is capable of resisting softening at high temperature, because of its property termed as____________________?
(A) Hot temper
(B) Hot hardness
(C) Fatigue
(D) Creep
When an isolated thermodynamic system executes a process ___________________?
(A) Work is done
(B) Heat transfer takes place
(C) Mass flow occurs across the boundary of the system
(D) No chemical reaction takes place within the system
The amount of water evaporated in kg per kg of fuel burnt in a boiler is called the ______________ of a boiler ?
(A) Evaporative capacity
(B) Evaporation efficiency
(C) Thermal efficiency
(D) Steam load
Thermal conductivity of a material does not depend upon its_____________________?
(A) Mass
(B) Volume
(C) Surface area
(D) All A, C & C