NivaarExam Prep

23-Chem-A2 Unit Operations and Separation Processes

Worked solutions to 14 past sittings (2013–2019), 84 questions. Pick a sitting, or start from a topic below.

Topics across the sittings

Topics that come up in more than one sitting, taken from the headings of our worked solutions. A topic counts once per sitting.

Questions by sitting

December 2019

  1. Question 1: Pump Power for Liquid Transfer Between Tanks
  2. Question 2: Terminal Velocity and Matched Fluidized-Bed Densities
  3. Question 3: Constant-Pressure Plate-and-Frame Filtration
  4. Question 4: Countercurrent Rotary-Drier Air Rate
  5. Question 5: Swenson–Walker Crystallizer Sizing
  6. Question 6: Double-Effect Forward-Feed Evaporator Capacity

December 2018

  1. Question 1: Minimum Area of a Continuous Thickener
  2. Question 2: Frictional Pressure Drop in Series Pipes with a Reducer
  3. Question 3: Pressure Drop and Power for Gas Flow through a Bed
  4. Question 4: Flash vs. Differential Distillation of Benzene–Toluene
  5. Question 5: Batch Drying Time (Constant + Falling Rate)
  6. Question 6: Adsorption Isotherm Selection and Surface Area

May 2018

  1. Question 1: Washing of a Filter Cake — Porosity, Density and Solute Loading
  2. Question 2: Pump Power for Pipe Flow with Fittings
  3. Question 3: Velocity to Just Lift a Particle (Free Settling)
  4. Question 4: Diameter and Pressure Drop of a Packed Absorption Tower
  5. Question 5: Langmuir and Freundlich Isotherms for Papain Adsorption
  6. Question 6: Two-Stage Cross-Current Liquid–Liquid Extraction

December 2017

  1. Question 1: Loss Factor of a Valve from Bench-Test Data
  2. Question 2: Maximum Efficiency of a Centrifugal Pump
  3. Question 3: Critical Particle Size in a Settling Lagoon
  4. Question 4: Part B — Separation Processes
  5. Question 5: Batch Drying Time of a Wet Slab
  6. Question 6: Design of a Batch Evaporative KCl Crystallizer

May 2017

  1. Question 1: Sizing a Flow Nozzle for an Ethanol Line
  2. Question 2: Swenson–Walker Copperas Crystalliser
  3. Question 3: Constant-Pressure Filtration of a CaCO₃ Slurry
  4. Question 4: Part B — Separation Processes
  5. Question 5: Drying-Rate Curve from Tray-Drying Data
  6. Question 6: Packed-Tower Height for Air Drying with Caustic

December 2016

  1. Question 1: Pump Power for a Crude-Oil Transfer Line
  2. Question 2: Minimum-Fluidization and Transport Mass Flux
  3. Question 3: Rotary-Drum Filter Speed and Throughput
  4. Question 4: Yield from Cooling Crystallization of KNO 3
  5. Question 5: Countercurrent Rotary Dryer Air Rate
  6. Question 6: Overall Coefficient of a Tubular Heat Exchanger

May 2016

  1. Question 1: Affinity-Law Scale-Up of a Centrifugal Pump
  2. Question 2: Terminal Velocity and Equal-Bed-Density Fluidization
  3. Question 3: Constant-Pressure Plate-and-Frame Filtration
  4. Question 4: Cooling Crystallization of Glauber's Salt
  5. Question 5: Single-Effect Caustic-Soda Evaporator Area
  6. Question 6: Additional Magnesia Insulation on a Hot Pipe

December 2015

  1. Question 1: Voidage of a Segregated Two-Size Fluidized Bed
  2. Question 2: Optimum Cycle Time of a Constant-Rate / Constant-Pressure Filter
  3. Question 3: Time to Fill a Buffer Tank — Laminar vs. Turbulent Limits
  4. Question 4: Natural-Convection Heat Transfer to a Long Square Duct
  5. Question 5: Steam Consumption and Area of a Single-Effect Evaporator
  6. Question 6: Sizing a Tubular (Water-to-Water) Heat Exchanger

May 2015

  1. Question 1: Pump Power for a Sanitary Apple-Juice Line
  2. Question 2: Settling Velocity to Minimum-Fluidization Velocity Ratio
  3. Question 3: Which Cooling Pipe Gives the Least Pressure Drop?
  4. Question 4: Free versus Forced Convection from a Vertical Plate
  5. Question 5: Maximum Feed Rate to a Double-Effect Evaporator
  6. Question 6: Steam Condenser Sizing and Tube Count

December 2014

  1. Question 1: Parallel-Pipe Flow Split and Equivalent Single Pipe
  2. Question 2: Plate-and-Frame Filter Press — Constant-Pressure Filtration
  3. Question 3: Terminal Settling Velocity of Solid Particles
  4. Question 4: Furnace Wall with Added Insulation
  5. Question 5: Swenson–Walker Crystalliser for Glauber's Salt
  6. Question 6: Tubular Condenser — Restoring Duty After Fouling

May 2014

  1. Question 1: Elevation Difference Between Two Reservoirs
  2. Question 2: Turbine-Mixer Power and Scale-Up
  3. Question 3: Rotary-Drum Vacuum Filter Throughput
  4. Question 4: Heater Between Two Composite Walls
  5. Question 5: Wall Shear Stress from a Heat-Transfer Correlation
  6. Question 6: Cross-Flow Heat Exchanger — Overall Coefficient

December 2013

  1. Question 1: Water-Delivery Pipe Network
  2. Question 2: Packed-Bed Reynolds Number
  3. Question 3: Hydrometer Densities and Centrifuge Interface
  4. Question 4: Section B — Thermal Operations
  5. Question 5: Finned-Pipe Heat Transfer
  6. Question 6: Tubular Heat-Exchanger Sizing

May 2013

  1. Question 1: Elevated-Tank Discharge — Required Head
  2. Question 2: Adiabatic Choked Relief Flow of Nitrogen
  3. Question 3: Packed-Bed Reactor — Porosity, Pellet Size, Area and Pressure Drop
  4. Question 4: Section B — Thermal Operations
  5. Question 5: Cross-Flow Heat Exchanger — Required Area
  6. Question 6: Radiative Cooling of a Brass Rod

Undated paper

  1. Question 1: Rate of Wash-Water Flow through a Batch Centrifugal Filter
  2. Question 2: Diameter of a Smooth Pipe from a Measured Pressure Drop
  3. Question 3: Pressure Drop through a Bed of Ion-Exchange Resin
  4. Question 4: Number of Transfer Units for a Packed Distillation Tower
  5. Question 5: Absorber Operating Line in Solute-Free Coordinates
  6. Question 6: SO₂ Adsorption Isotherm and Surface Area