⚗️ Chemical Engineering Solved MCQs with Answers

Practice 1920 approved ⚗️ Chemical Engineering questions with verified answers from the 🛠️ Engineering Essentials subject for Pakistan exams.

1920 solved MCQs

The slope of operating line in the rectifying section of a distillation column is unity, if the reflux ratio isAnswer: ∞ Vertical vessels are not supported byAnswer: Saddles With increase in pressure drop (for a given particle size), the dust collection efficiency of a cyclone separator willAnswer: Increase Spherical shaped pressure vessel is considered to be the most ideal, because it canAnswer: Withstand higher pressure for a given metallic shell thickness. An adequate clearance between the tray and the shell wall of a distillation column is provided toAnswer: Allow for thermal expansion and facilitate installation. Overall tray efficiency of a distillation column is the ratio of the number ofAnswer: Ideal trays required to the number of real trays required. Pick out the wrong statement about the design of a sieve plate column.Answer: Minimum recommended downcomer residence time for the disengagement of entrained vapour is the same for both foaming and non-foaming liquids, which is about 20 seconds. Generally, no corrosion allowance in wall thickness of a part is required, if the thickness is more than __________ mm.Answer: 30 Multiple blade paddle agitator is used for mixing high viscosity liquids/paste in which the paddle diameter is commonly 0.8 times the tank diameter. However, the width of the blade is in the range of __________ times the paddle diameter.Answer: 0.1 to 0.25 In a __________ rivetted joint, the rivets in the various rows are opposite to each other.Answer: Chain Pick out the wrong statement pertaining to the comparative evaluation of performance of the packed tower and the plate tower.Answer: The total weight of a dry plate tower is usually much more than that of a dry packed tower designed for the same duty. The circumferential (hoop) stress in a thin walled cylinderical vessel under internal pressure isAnswer: pd/2t LMTD correction factor is used in heat exchanger design forAnswer: Multipass shell and tube heat exchanger. Floating head heat exchangers are used for theAnswer: Cases where temperature difference between the shell and the tubes is more (>50°C). The most common standard size of bubble caps used in industrial operation isAnswer: 6" dia cap with 4" dia riser. Compensation against openings in process vessels for giving inlet and outlet connections, for providing sight glasses and manholes etc. is provided for strength and rigidity. The most efficient type of compensation is of __________ type.Answer: Nozzle or rim In case of a continuous distillation column, increase in reflux ratio may result in theAnswer: All (a), (b) and (c). In a distillation column, the minimum residence time for liquid in the downspout is about __________ seconds.Answer: 8 Thickness of the frame of a plate and frame filter as compared to that of plates isAnswer: More Which of the following factors affect the pressure drop in a co-current gas-liquid absorption packed tower ?Answer: All (a), (b) and (c). The thickness of heat transfer plates used in the plate type heat exchanger ranges from __________ mm, pressed in a single piece provided with grooves & corrugations.Answer: 1.25 to 3.125 Rivets are generally specified by theAnswer: Shank diameter Length to diameter ratio of most rotary driers is in the range ofAnswer: 4 to 10 Sewage is not an excellent medium for the growth ofAnswer: Aquatic creatures. Which of the following pair is correctly matched?Answer: All 'a', 'b' & 'c' are correctly matched. Rate of chemical reaction is not much affected, if the reactants are in __________ form.Answer: Either (a) or (b) Materials used for making permanent magnets containing iron and nickel are made by __________ technique.Answer: Forging Lubrication is done to controlAnswer: All (a), (b) & (c) Lead is most readily dissolved inAnswer: Acetic acid Which of the following is a synthetic abrasive ?Answer: Silicon carbide