Chemical Engineering Interview Questions
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In a furnace, 2 chemical reactions are happening – 1 mole of solid carbon reacts with 1 mole of oxygen gas to generate 1 mole of carbon dioxide gas; 1 mole of solid carbon reacts with 0.5 mole of oxygen gas to generate 1 mole of carbon monoxide gas. In a given process, 100 kmol of carbon is burned in a furnace. (a) Calculate the theoretical oxygen gas needed by assuming that all the carbon is burned completely to carbon dioxide gas. (b) Calculate the theoretical air needed by assuming that all the carbon is burned completely to carbon dioxide gas and there is only 21 % of oxygen gas. (c) Determine the amount of air required (in kmol) if 50 % excess oxygen gas must be satisfied for (a) and (b). (d) It has latter been found that 20 % of the carbon undergoes incomplete combustion resulting to carbon monoxide gas production. The rest of the carbon undergoes complete combustion. Calculate the total oxygen gas required stoichiometrically based on the actual process.

1 1940

Question 10 - In the US (United States), one barrel is equal to 42 US gallons and equivalent to 0.15898 cubic metres. One British barrel is equal to 36 Imperial gallons and equivalent to 0.163659 cubic metres. If an oil refinery in England sells 42 Imperial gallons of crude oil to a company in US, how much US gallons of crude oils has been sold?

1 1773

In Pressure Sfety Valve(PSV) 2" by pass line why given for process units.

Essar,

1544

The water is superheated steam at 440 degree Celsius and 17.32 megapascals. Estimate the enthalpy of the steam above. From the steam table for water at 440 degree Celsius, enthalpy of steam, h at 18 megapascals is 3103.7 kilojoules per kilogram and at 16 megapascal is 3062.8 kilojoules per kilogram. Assume that h = mP c where P is pressure; m and c are constants at fixed temperature with small differences in P.

1 1953

Hi, I want to validate an analytical procedure of a specified impurity, but this impurity is unavailable for me. can I use the API instead of impurity in the linearity test? in Which reference can I find such information?

Pharma,

1295

In a triple effect evaporator, the heat transfer for an evaporator is calculated as q = UA (TI – TF) where TI is the initial temperature, TF is the final temperature; U and A are constants. Given that heat transfer for the first evaporator : q(1) = UA (TI – TB); second evaporator : q(2) = UA (TB – TC); third evaporator : q(3) = UA (TC – TF) where q(x) is the heat transfer function, TB is the temperature of second inlet and TC is the temperature of third inlet, prove that the overall heat transfer Q = q(1) q(2) q(3) = UA (TI – TF).

1 2022

Calculate the cooling duty, H required to condense and cool acetone from 100 degree Celsius to 25 degree Celsius at atmospheric pressure. The heat of vaporization for acetone at its normal boiling point is 30.2 kJ / mol. The boiling point of acetone at atmospheric pressure is 56 degree Celsius. The flowrate of acetone through the condenser is 100 mol / s = N. Value of sensible heat needed to increase the temperature of acetone in liquid form from 25 to 56 degree Celsius is 4.06 kJ / mol. Value of sensible heat needed to increase the temperature of acetone in vapor form from 56 to 100 degree Celsius is 3.82 kJ / mol. Unit of H is kJ / s.

1 3688

A 1.5 weight % aqueous salt solution is concentrated to 4 weight % in a single-effect evaporator. The feed rate to the evaporator is F = 7500 kg / h and the feed is at 85 degree Celsius. The evaporator operates at 1 bar. By assuming that only pure solvent of water exists in the form of vapor from the feed, calculate the flow rate of such vapor V.

1 3499

In engineering economy, the future value of first year is FV = PV (1 i). For second year it is FV = PV (1 i) (1 i). For third year it is FV = PV (1 i) (1 i)(1 i) where FV = future value, PV = present value, i = interest rate per period, n = the number of compounding periods. By induction, what is the future value of $1000 for 5 years at the interest rate of 6%?

1 2276

SSR meanig

1 1979

A concentric, counter-current heat exchanger is used to cool lubricating oil. Water is used as the coolant. The mass flow rate of oil into the heat exchanger is 0.1 kg / s = FO. For oil, the inlet temperature TIO = 100 degree Celsius and the outlet temperature TOO = 55 degree Celsius. For water, the inlet temperature TIW = 35 degree Celsius and the outlet temperature TOW = 42 degree Celsius. What is the mass flow rate of water in kg / s, FW needed to maintain these operating conditions? Constant for heat capacity of oil is CO = 2131 J /(kg K) and for water is CW = 4178 J /(kg K). Use the equation (FO)(CO)(TIO – TOO) = (FW)(CW)(TOW – TIW).

1 1936

Water flows through a pipe with circular cross sectional area at the rate of V / t = 80 L / s where V is the volume and t is time. Let Av = 80 L / s where A is cross sectional area and v is velocity of fluid. For point 1, the radius of the pipe is 16 cm. For point 2, the radius of the pipe is 8 cm. Find (a) the velocity at point 1; (b) the velocity at point 2; (c) the pressure at point 2 by using Bernoulli’s equation where P Rgy 0.5 RV = constant. P is the pressure, R = density of fluid, V = square of fluid’s velocity, g = gravitational constant of 9.81 N / kg and y = 2 m = difference of height at 2 points. The pressure of point 1 is 180 kPa.

1 1897

A cylinder with a movable piston contains 0.1 mole of a monoatomic ideal gas. The piston moves through state a, b and c. The heat Q, changes from state c to a is 685 J. The work W, changes from state c to a is -120 J. The work, W performed from state a to b then to c is 75 J. By using the first law of thermodynamic, U = Q W where U is the internal energy : (a) Determine the change in internal energy between states a and c. (b) Is heat added or removed from the gas when the gas is taken along the path abc? (c) Calculate the heat added or removed when the gas is taken along the path abc?

1 3636

Is four stage graphite steam jet ejector is possible. Any body can provide its design

Atul,

1445

What is the meaning – strain? In a distillation column, if a metal block 10 cm on a side is deformed so that it becomes 9 cm long due to cooling effect, what is the strain involved in percentage?

1 1728


Post New Chemical Engineering Questions

Un-Answered Questions { Chemical Engineering }

How can you determine the proper pipe thickness for a slurry line?

610


For a heat exchanger, will the overall heat transfer coefficient increase along with an increase in lmtd (log mean temperature difference) around the unit?

608


Name some factors to consider when trying choosing between a dry screw compressor and an oil-flooded screw compressor?

527


What is the ignititon temprecher of Diesel,Petrol&Carosion oil.

2659


Hi, I am preparing for Indian Forest Service (UPSC). Can you please help me to get previous years question papers (Chemcial Engineerign) (atleast 5).

4051






what is the difference between car seal close/open valves and lock close/open valves?

4934


Why do we apply on iron articles?

620


How can separation of chiral chemicals affect the chemical and/or pharmaceutical industries?

587


Why in a continuous plant for a Hot standby screw pump system the interlock for auto starting of the other pump ( when the running pump stopped suddenly) is given with header pressure only? why not with flow rate or current of the pump?

1364


Explain what are some common precipitating agents used to remove metals from aqueous waste streams?

579


What is the average salary for chemical engineers?

576


What are some of the consequences of an undersized kettle type reboiler?

625


What are the different ways in which solids can be blended?

614


Explain some common piping materials used to transport slurries?

584


Name some common causes of control valve noise?

574