Day 2 - Chemical Engineering Principles Flashcards
(146 cards)
1
Q
Direct function of the range of an instrument which is the ratio of the upper range value of the instrument to the lower range value.
A
Span
2
Q
Heat capacity is defined as C = dQ/dT. What is the difficulty about the relationship of C to Q which are supposedly state functions.
A
They are process dependent quantities. Meaning they are path functions, not state functions.
3
Q
Flow equation applicable to Vnotch weir.
A
V/O = 2.505 (tan A/2) ^0.996 H^2.67
4
Q
Controller known for their versatility in systems which respond rather sluggishly.
A
Integral control
5
Q
In operating a batch filter.
A
Keep pressure constant, increase rate of flow.
6
Q
True or False: Specific molar volume and specific molar density are intensive thermodynamic variables.
A
F
7
Q
Exists in forced convection though their effects are small.
A
External forces
8
Q
Who introduced the first standard screw thread.
A
Whitworth
9
Q
In a metal plating plant in Cagayan de Oro and Iligan, the waste
contains 20 mg/L Cu2+. It was decided that no precipitate most of
copper in the water, Ca(OH)2 will be used, until only 0.5 mg/L of
Cu remains. Estimate the OH- Concentration in moles/L.
A
1.6x10^-7 mol/L
Memorize the answer to this!
10
Q
Most penetrating radiation
A
Gamma ray
11
Q
Nucleophile of chymotrypsin reaction.
A
Serine
12
Q
What did Marie Curie discover.
A
Radium and Polonium
13
Q
True or False: Positive ions have smaller size than neutral atom.
A
True
14
Q
How do you differentiate electromagnetic radiation? Wavelength
A
Frequency and Wavelength (accrdng to AI)
15
Q
What is the resultant pH if you open a can of soda?
A
Increase
16
Q
True or False. Lower altitude = higher partial pressure.
A
True
17
Q
Carnot Engine is composed of….
A
Two isothermal and two isentropic processes.
18
Q
Melting of ice is exothermic or endothermic?
A
Endothermic
19
Q
Illustrates fresh water.
A
Sea green
20
Q
Heat sensitive materials can be concentrated in an evaporator
employing
A
Vacuum
21
Q
kg of liquid evaporated per hour in an evaporator is defined as its
A
capacity
22
Q
The number of kg vaporized per kg of steam fed to the evaporator is defined as
A
Economy
23
Q
What is the steam economy in case of a single effect evaporator
system?
A
<1
24
Q
Evaporation of 1kg of water from a solution in a single effect
evaporator requires about __________ kg of steam.
A
1-1.3
25
The rate of heat transfer is a product of overall heat transfer coefficient, the difference in temperature and the
Heat transfer area
26
Increasing the liquor level in the evaporator results in the
Decreased capacity
27
It is not preferable to use superheated steam in evaporators,
because of its very
Low film coefficient
28
Small scale evaporation is done in a
Steam jacketed kettle
29
Viscous and heat sensitive liquids are concentrated in __________
evaporators.
Agitated film
30
Forced circulation evaporators are useful for the concentration of
viscous, salting and scale forming liquors. Which of the following is a
forced circulation evaporator?
Agitated film evaporator
31
A __________ evaporator employs an annular down take.
Basket type
32
Which is the most suitable for the concentration of foamy and frothy liquors?
Long tube vertical evaporator
33
Boiling point elevation for a strong and concentrated solution is
found by Duhring's rule, which states that at the same pressure, the
boiling point of a solution is a linear function of the __________ of
pure water
Boiling point
34
Boiling point of a solution according to Duhring's rule is a linear
function of the __________ of water.
Boiling point at the same pressure
35
In case of vertical tube evaporator, with increase in liquor level, the
overall heat transfer coefficient
Decreases
36
In case of evaporators, liquid entrainment results primarily due to
Foaming of the solution
37
Multiple effect evaporation is generally recommended, when the
large scale evaporation of liquor is needed.
38
A dilute aqueous solution is to be concentrated in an evaporator
system. High pressure steam is available. Multiple effect evaporator
system is employed, because
total amount of vapor produced per kg of feed steam in a multiple
effect system is much higher than in a single effect.
39
In a backward feed multiple effect evaporator
Feed flows from low pressure to high pressure
40
For evaporation of viscous solution in a multiple effect evaporator,
the preferred feeding scheme is
Backward
41
In a forward feed multiple effect, the pressure build up will be
least at the outlet of the last effect
42
For the same heat transfer area and the terminal conditions, the ratio
of the capacities of a single effect evaporator to a triple effect
evaporator is
a. 3
b. 1
c. 0.33
d. 1.33
B. 1
43
Black liquor generated during paper manufacture is concentrated in
a
multiple effect evaporator
44
accessories is provided in the vapor line of an evaporator for removing the entrained liquid?
Catchall
45
The driving potential for the crystal growth during crystallization is the
__________ of the solution.
Super - saturation
46
Crystallization of solids from a homogeneous solution is a/an
__________ process.
Exothermic
47
In most of the vacuum crystallizer, vacuum is generally produced by
means of a
steam jet ejector with a barometric condenser
48
At a fixed pressure, the humidity depends upon the partial pressure
of vapor in the mixture. Humidity of a vapor free gas is __________
percent.
zero
49
__________ is the temperature at which a gas-vapor mixture
becomes saturated, when cooled at constant total pressure out of
contact with a liquid.
Dew point
50
Weight of 1 m3 of humid air as compared to 1 m3 of dry air, under the
same conditions, is
less
51
When an unsaturated air-water mixture is heated at constant
pressure, then
the relative humidity decreases.
52
Condensation of a vapor-gas mixture just begins, when (where, p =
partial pressure of the vapor P = vapor pressure of the liquid)
Density = Pressure
53
Steady state temperature reached by a small amount of liquid
evaporating into a large amount of unsaturated vapor-gas mixture is
Wet bulb temperature
54
Which of the following remains constant during evaporative cooling
process with recirculated water supply?
Wet bulb temperature
55
When the temperature and humidity of air is low, we usually use
__________ draft cooling tower.
Natural
56
Air initially at 101. 3 kPa and 40°C and with a relative humidity of
50%, is cooled at constant pressure to 30°C. The cooled air has a
higher relative humidity
57
Moisture contained by a substance in excess of the equilibrium
moisture is called
Free moisture
58
Moisture in a substance exerting an equilibrium vapor pressure less
than that of pure liquid at the same temperature is called the
__________ moisture.
bound
59
Drying operation under vacuum is carried out to
reduce drying temperature.
60
A solid material shows case hardening properties while drying. Which of the following should be controlled to control the drying process?
Temperature of the solid
61
Milk is usually dried in a ____ dryer
Spray
62
Heat sensitive materials like certain pharmaceuticals and food stuff
can be dried
By freeze drying
63
Large scale drying of sugar is done in a __________ dryer.
Rotary
64
Free flowing granular materials can be best dried in a __________
drier.
Rotary
65
Pick out the wrong statement pertaining to the rotary dryer.
a. Flights (located in the inside shell of rotary dryer) lift the material
being dried and shower it down through the current of hot air/gases. It extends from the wall to a distance which is about 8-12% of the
inside diameter of shell.
b. Hold up of a rotary drier is defined as the fraction of the dryer
volume occupied by the solid at any instant. The best performance
for rotary drier is obtained, when the holdup is in the range of 0.05 to 0.15.
c. Rotary dryer is suitable for drying sticky material.
d. Recommended peripherial speed of a rotary drier is in the range
of 10 to 30 meters/minute.
C. Rotary dryer is suitable for drying sticky material.
66
Flights in a rotary dryer are provided to
lift and shower the solids thus exposing it thoroughly to the drying
action of the gas.
67
Which of the following is not a continuous drier?
a. Drum drier
b. Tunnel drier
c. Spray drier
d. Tray drier
D. Tray Drier
68
Emissions from leased buildings are typically categorized under?
Scope 3
69
What is carbon trading intended to do?
Cap emissions and create economic incentives for reduction
70
A carbon tax is intended to encourage emissions reduction through _______.
market pressure
71
The Clean Development Mechanism (CDM) allows _______.
Developed countries to invest in emission-reducing projects in developing countries
72
What does a carbon offset refer to?
Investment in projects that reduce or capture emissions
73
The term 'cradle-to-gate' in carbon accounting refers to?
Emissions from raw material extraction to factory gate
74
What is a typical emission factor used for calculating CO₂ from diesel combustion?
2.68 kg CO₂/L
75
How much CO₂ is emitted by a coal-fired power plant that emits 2.2 tons of CO₂ per MWh operating at 50 MW for 10 hours?
1100 tons
76
The Air Quality Index (AQI) includes which of the following parameters?
CO₂, PM, NO₂, O₃
77
Which gas has the highest global warming potential (GWP)?
SF6
78
What is the primary reaction mechanism behind the formation of tropospheric ozone?
VOCs and NOx reacting under sunlight
79
Photochemical smog is typically formed in _______.
Urban centers under high sunlight
80
Afforestation helps mitigate climate change by _______.
Enhancing carbon sequestration
81
Carbon sequestration refers to _______.
Capturing and storing CO₂
82
What is the primary goal of carbon capture and storage (CCS)?
Remove carbon dioxide from the atmosphere
83
What is the primary environmental concern with hydrofluorocarbons (HFCs)?
High global warming potential
84
Which protocol was established to reduce greenhouse gas emissions?
Kyoto Protocol
85
Which of the following gases is not included in the Kyoto Protocol's 'basket of six' GHGs?
NH₃
86
What is the goal of the Paris Agreement?
Keep global warming below 2°C
87
Which of the following best describes 'extended producer responsibility' (EPR)?
A program that encourages producers to take responsibility for the entire lifecycle of their products, including disposal
88
Which of the following best defines 'environmental impact assessment' (EIA)?
A procedure for evaluating the potential environmental consequences of a proposed project or development
89
The primary environmental impact of urban sprawl is _______.
Decreased air quality due to increased vehicle emissions
90
A wind turbine has a capacity factor of 35% and a rated capacity of 2 MW. How much energy (MWh) does it produce annually?
6,132 MWh
91
What is the purpose of aeration in water treatment?
Oxidation of iron and manganese
## Footnote
Aeration helps in the removal of dissolved gases and enhances the oxidation process in water treatment.
92
What is the primary advantage of using ozone for water disinfection?
It is more effective than chlorine against viruses
## Footnote
Ozone does not produce harmful byproducts unlike some chlorine compounds.
93
The main advantage of trickling filter over activated sludge is:
Lower power requirement
## Footnote
Trickling filters utilize less energy compared to activated sludge systems.
94
Sludge from primary settling tanks is mostly composed of:
Settleable organic solids
## Footnote
This sludge primarily contains organic matter that can be further treated.
95
What is the primary advantage of using anaerobic digestion in wastewater treatment?
It reduces the volume of sludge generated and produces biogas
## Footnote
Anaerobic digestion is an effective method for waste stabilization and energy recovery.
96
The final stage of wastewater treatment often involves:
Disinfection
## Footnote
Disinfection is crucial to eliminate pathogens before effluent discharge.
97
If a municipal water treatment plant has a flow rate of 20,000 m³/day and the required alum dosage is 20 mg/L, how much alum (in kg) is needed per day?
400 kg
## Footnote
Alum is used for coagulation in water treatment processes.
98
A sludge thickener processes 500 m³/day of sludge with an initial solid content of 2%. If the thickened sludge has a solid content of 5%, what is the final sludge volume (m³/day)?
200 m³/day
## Footnote
Thickening reduces the volume while increasing solid concentration.
99
The biochemical oxygen demand (BOD) of a water sample measures:
Organic pollutants
## Footnote
BOD indicates the amount of oxygen required by microorganisms to decompose organic material.
100
In BOD testing, why is dilution of the sample often required?
To avoid complete oxygen depletion
## Footnote
Dilution prevents the sample from consuming all available oxygen during testing.
101
COD is preferred over BOD when:
Time constraints exist.
## Footnote
COD provides a quicker measurement of organic pollutants.
102
Which reagent is used in the standard COD test?
Potassium dichromate
## Footnote
Potassium dichromate is used for oxidizing organic matter in the sample.
103
If BOD is greater than COD, it indicates:
Error in measurement.
BOD is for organic pollutants. While COD is both for organic and inorganic pollutants.
104
What is the typical COD/BOD ratio for domestic wastewater?
1.5-2.5
## Footnote
This ratio helps assess the treatability of wastewater.
105
A wastewater sample contains 250 mg/L COD and 200 mg/L BOD. What is the biodegradability index?
0.8
## Footnote
The biodegradability index helps understand the organic matter's treatability.
106
A wastewater treatment plant treats 50,000 m³/day with an influent BOD of 250 mg/L and an effluent BOD of 30 mg/L. What is the daily BOD load removed (kg)?
11,000 kg
## Footnote
The BOD load removed indicates the effectiveness of the treatment process.
107
The COD of a wastewater sample is 400 mg/L. If the sample volume is 2 liters, how much oxygen (mg) is required for complete oxidation?
800 mg
## Footnote
COD values indicate the amount of oxygen needed for oxidation of organic material.
108
The term 'carbon footprint' refers to:
All greenhouse gas emissions in CO₂ equivalent (CO₂e)
## Footnote
Carbon footprint encompasses total emissions from various sources.
109
Which gas is excluded when calculating carbon dioxide equivalent?
Methane
## Footnote
Methane is considered separately due to its different impact on global warming.
110
Carbon intensity refers to:
CO₂ emitted per unit energy produced
## Footnote
This metric helps assess the efficiency and environmental impact of energy production.
111
Which sector contributes the most to global carbon emissions?
Electricity consumption
## Footnote
The energy sector is a significant contributor to greenhouse gas emissions.
112
What is the main source of carbon footprint in cement production?
Chemical decomposition of limestone
## Footnote
This process releases CO₂ during cement manufacturing.
113
Which of the following environmental issues is most directly linked to the increase in CO₂ concentration in the atmosphere?
Ocean acidification
## Footnote
Increased CO₂ levels lead to higher acidity in ocean waters, impacting marine life.
114
The most significant source of anthropogenic methane is:
Agriculture
## Footnote
Livestock and rice cultivation are major contributors to methane emissions.
115
The GHG Protocol divides emissions into how many Scopes?
3
## Footnote
Scopes 1, 2, and 3 categorize direct and indirect emissions.
116
Which sector is classified under Scope 3 emissions?
Emissions from upstream transportation
## Footnote
Scope 3 covers indirect emissions not controlled by the reporting company.
117
Which statement about Scope 2 emissions is true?
They arise from purchased energy
## Footnote
Scope 2 emissions are associated with the consumption of electricity, heating, and cooling.
118
What is the theory that describes the settling of particles heavier than water under gravity?
Screening
## Footnote
This process involves removing settleable particles through gravitational influence.
119
What process allows for the removal of coarse matter from flowing water using bars, fines wires, or rocks?
Screening
## Footnote
It involves straining out suspended or floating coarse matter.
120
Which of the following is NOT a secondary treatment process? a. Trickling filter b. Activated sludge process c. Anaerobic digestion d. Chlorination
Chlorination
## Footnote
Chlorination is typically considered a disinfection process rather than secondary treatment.
121
What type of water treatment destroys disease-causing organisms and removes soluble irons, manganese, and hydrogen sulfide?
Chlorination
## Footnote
Disinfection alone does not remove irons, manganese, and hydrogen sulfide in water.
122
What is a code for plastics commonly used in food wrapping, trash bags, and grocery bags?
RA 9003
## Footnote
This regulation governs the management of solid waste in the Philippines.
123
What international treaty serves as the primary basis for the Philippines in its environmental dispute with Canada?
Basel Convention
## Footnote
This treaty relates to the control of transboundary movements of hazardous wastes.
124
What is the Ecological Solid Waste Act of 2000 also known as?
RA 9003
## Footnote
This act provides the framework for ecological solid waste management in the Philippines.
125
What does 'Smokey Mountain' refer to in the context of solid waste?
Open dumping site
## Footnote
It is a well-known example of a large waste disposal area.
126
What is the global treaty designed to phase out chlorofluorocarbons?
Montreal Protocol
## Footnote
This treaty is critical for protecting the ozone layer.
127
What is the collective term for the initial POPs identified by the Stockholm Convention?
Dirty Dozens
## Footnote
These are the first twelve persistent organic pollutants targeted for elimination.
128
What gas is odorless, colorless, and lethal to humans at concentrations exceeding 5000 ppm?
Carbon monoxide
## Footnote
This gas can bind with hemoglobin, preventing oxygen transport in the body.
129
Is the statement 'The concentric atmosphere layer just above troposphere is called stratosphere, which is rich in ozone' true or false?
True
## Footnote
The stratosphere contains a significant amount of ozone.
130
What is the rate at which temperature in the atmosphere changes with altitude called?
Lapse rate
## Footnote
This term describes the temperature decrease with increasing altitude.
131
Which combination of acids is dominant in acid rain?
Nitric acid and sulfuric acid
## Footnote
These acids contribute significantly to the acidity of rainwater.
132
What is the primary purpose of coagulation in water treatment?
Destabilize suspended particles
## Footnote
Coagulation is essential for removing fine particles from water.
133
Which common coagulant is used in water treatment?
Aluminum sulfate
## Footnote
This chemical is widely used for coagulation processes.
134
What is the role of a flocculant in water treatment?
Helps in aggregation of fine particles
## Footnote
Flocculants aid in the formation of larger aggregates to facilitate removal.
135
Reverse osmosis (RO) is mainly used to remove what from water?
Dissolved salts
## Footnote
RO is effective in desalination processes.
136
What is the main drawback of using activated carbon in water treatment?
It has a limited adsorption capacity and needs frequent replacement
## Footnote
This limits its long-term effectiveness.
137
Which process is used to remove phosphorus from wastewater?
Chemical precipitation with alum or ferric chloride
## Footnote
This method is effective in reducing phosphorus levels.
138
What is the most common method for removing nitrates from water?
Ion exchange
## Footnote
This method is widely used in water treatment facilities.
139
What is the main function of a rapid sand filter?
Remove remaining turbidity after sedimentation
## Footnote
Rapid sand filters enhance water clarity.
140
Which method is considered the best for removing arsenic from water?
Reverse osmosis
## Footnote
RO is effective in eliminating arsenic contamination.
141
In heat exchanger, floating head is applied for
Expansion
142
Van laar equation is used for
Binary solutions
143
Which of the following material is seldom used for pressure vessel construction
Rimmed Steel
144
25% cut segmental baffle means that the baffle
Heist is 75% of inside diameter
145
Le/D for fully open globe valve may be around
300
146
