Chemical Engineering Interview Questions and Answers
This article will give you the list of subject specific questions frequently asked during interview. For Personal profile related and experience related questions refer General engineering interview questions
Chemical engineering implies to the study of chemical and biological processes and design of industrial scale equipment for a cost and time efficient as well as safe production. It is also known as process engineering. Since chemical engineering involves the fields of sciences like physics, chemistry, biology and fields of engineering like equipment design, cost and time optimization, chemical engineers are subjected to a wide variety of questions. Chemical engineers can expect the following questions in an interview.
- Explain the third law of thermodynamics.
The third law states that 'As a system approaches absolute zero, the entropy of the system approaches a minimum value'.
- What is entropy?
Entropy is a measure of disorderliness. It explains the system's closeness to equilibrium.
- What is Gibbs free energy?
It is the available energy or the greatest amount of mechanical work done by a system at constant temperature and pressure.
- At what temperature does water have maximum density?
At 4 deg C the density of water is 1000 kg/cu.m.
- What is an isochoric process?
It is a thermodynamic process at constant volume. Also called isovolumetric process
- What is a CSTR and what are its basic assumptions?
Continuous Stirred tank Reactor. Assumptions are steady state, constant density, constant temperature, one irreversible first-order reaction.
- List the advantages and disadvantages of a PFR.
Advantages: Continuous operation, high conversion rate, less cost for operation. Disadvantages: temperature gradients, high maintenance cost.
- Explain the functioning of a three-way catalytic converter.
Carbon monoxide oxidation, Nitrogen oxide reduction, uncombusted hydrocarbon oxidation.
- Explain global warming from a common man's and an engineer's perspective.
In a common man's perspective, the increase in world temperatures is global warming. In an engineer's perspective, it is the average temperature increase in the surface temperature of the earth, mainly due to increased concentration of greenhouse gases. The greenhouse gases capture the heat radiated by the earth, inside the atmosphere, enabling the increase in temperature.
- What is carbon sequestration?
A technique for capturing carbon dioxide for a long term in order to reduce its effects on global warming.
- What are the greenhouse gases in earth's atmosphere?
Water vapor, carbon dioxide, ozone, methane, nitrous oxide and CFC.
- Define octane number.
It is the resistance to detonation of a fuel in a spark ignition engine compared to the isooctane-n-heptane mixture.
- Explain the working of a spray condenser
A spray condenser is used for the condensation of humid water vapor by direct contact with water. The inlet water is at a temperature less than the dew point of air in the chamber.
- How does a cyclone separator work?
It works as gas-solid separation equipment using vortex formation.
- Define viscosity.
Viscosity is a measure of a fluid's resistance to shear stress.
- What is critical radius of insulation?
The critical radius of insulation is the thickness of an insulation that does not affect the convection resistance. It is the ratio of the thermal conductivity of the insulator to the convection heat transfer coefficient.
- What is a black body?
An ideal object that absorbs all electromagnetic radiations.