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Worksheets22BT34 - AAT 1
Total questions: 30
Worksheet time: 26mins
The Bernoulli equation states that P/ρg + v²/2g + z = constant. If water flows from a tank (point 1: v₁≈0, z₁=10m, P₁=atm) through a pipe to point 2 (z₂=2m, P₂=atm), what is the approximate velocity at point 2? (g=10 m/s²)
8.9 m/s
12.6 m/s
14.1 m/s
10.0 m/s
In bioprocess flowsheets, which sequence is MOST appropriate for a typical fermentation-based production process?
Sterilization → Fermentation → Centrifugation → Filtration → Chromatography → Drying
Fermentation → Sterilization → Extraction → Drying → Filtration
Filtration → Fermentation → Sterilization → Centrifugation → Extraction
Centrifugation → Fermentation → Filtration → Sterilization → Drying
A U-tube manometer contains mercury (ρ=13,600 kg/m³) and shows a height difference of 0.15 m. What is the pressure difference being measured? (g=9.8 m/s²)
(a)
Which statement BEST explains why single column manometers are preferred over U-tube manometers in industrial applications?
They can measure higher pressures
The reading is more direct as the reservoir level remains nearly constant
They work better with viscous fluids
They have higher sensitivity for small pressure differences
An orifice meter and venturi meter are installed in the same pipeline. Which statement is correct regarding their comparison?
Orifice meter has higher permanent pressure loss but is cheaper
Venturi meter has higher permanent pressure loss but higher accuracy
Both have identical pressure recovery characteristics
Orifice meter is more accurate for low Reynolds numbers
Convert 500 BTU to calories using the correct conversion factor.
(a)
According to Stokes' law, settling velocity v = (ρₚ-ρf)gd²/(18μ). If particle diameter doubles while all other factors remain constant, the settling velocity______
Doubles
Triples
Quadruples
Remains the same
For a sand filter removing small precipitate amounts from large water volumes, which characteristic is MOST important?
High filtration rate
Large surface area and depth for continuous operation
Low pressure drop
Easy cake removal
Which particle size analysis method would be MOST appropriate for analyzing protein aggregates in the 0.1-10 μm range?
Sieving
Sedimentation
Dynamic light scattering
Fluidization
In solid-liquid separation, hindered settling occurs when particle concentration is high. How does this affect settling velocity compared to free settling?
Increases velocity due to particle interaction
Decreases velocity due to increased effective viscosity
No effect on velocity
Velocity becomes independent of particle size
Which statement BEST explains why centrifugation is preferred over sedimentation for separating bacterial cells from fermentation broth?
Lower energy consumption
Larger capacity per unit
Faster separation due to much higher driving force
Better for heat-sensitive materials
In solid-liquid separation techniques, which method relies on the settling of particles under gravity?
Filtration
Fluidization
Sedimentation
Centrifugation
Fick's law states J = -D(dc/dx). For a diffusion coefficient of 2×10⁻⁹ m²/s, what is the correct unit interpretation?
Rate of mass transfer per unit time
Area per unit time representing diffusion rate
Concentration gradient
Flux per unit concentration difference
For a binary distillation with q = 0, what is the feed condition?
Subcooled liquid
Saturated liquid
Saturated vapor
Superheated vapor
The McCabe-Thiele method shows that a distillation column requires 8 theoretical stages at actual reflux ratio R = 2. If minimum reflux ratio Rmin = 1, what is the approximate number of stages at minimum reflux?
4
8
16
Infinite
Why is steam distillation particularly useful for separating heat-sensitive biomolecules?
Increases separation efficiency
Allows distillation at temperatures below 100°C at atmospheric pressure
Eliminates the need for vacuum equipment
Reduces energy consumption by 50%
Vapor-liquid equilibrium data shows that at 1 atm, benzene-toluene forms an ideal solution. At what composition is the vapor pressure highest?
Pure benzene
Pure toluene
50:50
It is constant across all compositions
An extraction column uses 200 kg/hr of solvent to extract 50 kg/hr of solute from 1000 kg/hr of feed. What is the solvent-to-feed ratio?
0.05
0.20
0.25
4.00
In leaching operations for biotechnology, what is the primary objective?
Increase viscosity of final product
Extract valuable components from solid materials using solvent
Reduce particle size of solids
Enhance heat transfer rate
A drying curve shows a constant rate period followed by a falling rate period. During the constant rate period, the drying rate is limited by:
Internal moisture diffusion in the solid
External heat and mass transfer conditions
Equilibrium moisture content
Critical moisture content
Activated carbon with a surface area of 1000 m²/g is used for adsorption. If the pore volume is 0.5 cm³/g, what does this indicate about the carbon's adsorption capacity?
Low capacity due to small pore volume
High capacity due to large surface area and adequate pore structure
Capacity depends only on particle size
Insufficient information to determine capacity
In batch adsorption, 10 g of activated carbon (m) is added to 1 L of solution containing 100 mg/L of solute (x). If equilibrium concentration is 20 mg/L, what is the adsorption capacity (x/m)?
2 mg/g
4 mg/g
8 mg/g
10 mg/g
A material has an initial moisture content of 40% (wet basis) and is dried to 10% (wet basis). What is the mass of water removed per 100 kg of wet feed?
30 kg
33.3 kg
36.7 kg
40 kg
In adsorption columns, breakthrough occurs when:
All adsorbent is saturated
Adsorbate first appears in effluent at detectable concentration
Maximum adsorption capacity is reached
Pressure drop becomes excessive
The Langmuir adsorption isotherm assumes:
Multilayer adsorption
Monolayer adsorption with no interaction between adsorbed molecules
Exponential relationship between coverage and concentration
Temperature-independent adsorption
What is the primary distinction between microfiltration and ultrafiltration?
Operating pressure
Pore size range (MF: 0.1-10 μm, UF: 1-100 nm)
Feed concentration
Temperature of operation
In size exclusion chromatography (SEC), which molecules elute first?
Smallest molecules
Largest molecules that cannot enter pores
Most charged molecules
Molecules with highest affinity for stationary phase
An ultrafiltration membrane with MWCO (Molecular Weight Cut-Off) of 10 kDa is used to concentrate a protein of 45 kDa. What would pass through the membrane?
All proteins including 45 kDa
Only molecules smaller than 10 kDa
Only molecules larger than 10 kDa
No molecules would pass
In affinity chromatography, the binding of target molecule to ligand is reversed by:
Increasing temperature only
Changing pH, ionic strength, or adding competing agent
Increasing pressure
Adding more sample
For purifying a 150 kDa antibody from a cell culture containing proteins ranging from 10-200 kDa, which chromatography sequence is MOST logical?
SEC → Ion Exchange → Affinity
Affinity → Ion Exchange → SEC
Ion Exchange → SEC → Affinity
SEC → Affinity → Ion Exchange
