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Correct answer is (b) 0

Easy explanation: The process is said to be operating at steady-STATE when all process variables do not CHANGE with time.

The accumulation term in a balance must equal to ZERO to ENSURE that the amount/mass of material in the process do not change with time.

Steady state means accumulation = 0

Input + generation – output – CONSUMPTION = 0

Input + generation = output + consumption.

Correct answer is (d) ORIGINAL-Liquid-in-place (OLIP)

Explanation: Material balance analysis is an INTERPRETATION method used to determine original fluids-in-place (OFIP) based on production and static PRESSURE data. The general material balance equation relates the original oil, gas, and water in the reservoir to production volumes and current pressure conditions / fluid PROPERTIES.

Right choice is (d) 2.09 g COD/g ETHANOL

The best I can explain: Ethanol (C2H5OH) has a DEGREE of reduction of 12 (MOL electrons/mol ethanol). Oxygen has a degree of reduction of -4 (mol electrons/mol oxygen)and a molecular WEIGHT of 32 g/mol, which corresponds to 8 g oxygen (=COD)/mol electrons. Multiplying 12 by 8, this results in 96 g COD/mol ethanol, or, 96/46 = 2.09 g COD/g ethanol.

The correct option is (d) 24

Easiest EXPLANATION: Glucose is C6H12O6. The DEGREE of reduction = 6 X (+4) + 12 x (+1) + 6 x (-2) = 24.

Right choice is (a) A ∼ A

Explanation: The equivalence relation is of reflexivity as an example of a reflexive relation is the relation “is equal to” on the SET of real numbers since EVERY real NUMBER is equal to itself. A reflexive relation is said to have the reflexive PROPERTY or is said to possess reflexivity. Along with symmetry and transitivity, reflexivity is one of three properties defining equivalence relations.

The correct option is (a) True

For explanation: BACTERIA TEND to have SLIGHTLY higher NITROGEN contents (11-14%) than fungi (6.3-9.0%).

The CORRECT answer is (a) Quantity of MIXED feed STREAM to the quantity of FRESH feed stream

Best EXPLANATION: Combined feed ratio is the ratio of the quantity of mixed feed stream to the quantity of fresh feed stream.

Combined feed ratio = M/F.

The correct answer is (a) 17,000 P/yr

Explanation: LET P denotes people,

INPUT + GENERATION – Output – Consumption = accumulation

80,000 P/yr + 18,000 P/yr – 70,000 P/yr – 11,000 P/yr = A(P/yr)

A = 17,000 P/yr

Each YEAR the city’s population increases by 17,000 P/yr.

The CORRECT option is (c) Hydrostatic equilibrium

Explanation: In fluid mechanics, a fluid is said to be in hydrostatic equilibrium or hydrostatic balance when it is at rest, or when the FLOW velocity at each point is constant over time. This occurs when external forces such as GRAVITY are balanced by a PRESSURE gradient FORCE.

Correct answer is (c) Electrical resistance (Parallel)

To explain: When TWO wires with electrical resistances R1 and R2 are connected in series than the TOTAL resistance is an extensive quantity Rtotal = R1 + R2, but when the wires are connected in parallel the total resistance is not extensive 1/Rtotal = 1/R1 + 1/R2. THEREFORE, electrical resistance is not an extensive nor INTENSIVE quantity.

The CORRECT option is (d) 4

The best explanation: We can write 4 BALANCE equations: A TOTAL balance equation and 3 component balance equations.

Independent balances: Not all balances are independent SINCE the total balance is the SUM of all of the component balances.

Thus, the number of independent balances we can write = the number of components.

The correct answer is (b) By-pass system

To elaborate: A by-pass is one where a portion of the inlet to a process unit is split from the feed and instead of entering the process is combined with the outlet from that process. This practice is far less common than RECYCLE, but may be USED if your ultimate goal is a material with PROPERTIES” in-between” the UNTREATED reactant and the process outlet product.

The correct choice is (d) Continuous process

Explanation: Amounts of mass entering and leaving the system are specified USING flow rates, a mass balance based on rates is called a differential balance. WHEREAS, each term of the mass-balance equation in this case is a quantity of mass, not a RATE. This type of balance is called an integral balance. Differential balances for continuous SYSTEMS operating at steady state and integral balances for batch and semi-batch systems between INITIAL and final states are used.

Correct option is (b) γ = 6

To elaborate: Ethanol (C2H5OH) = 2(4) + 6(1) + 1(-2) = 12,

γ = 12/2 = 6

As, the number of equivalents of available ELECTRONS per GRAM atom C is the measure of degree of reduction.

Correct OPTION is (b) 97

Easiest explanation: Mg (Magnesium) + 2 HCL (Hydrochloric acid) = MgCl2 (Magnesium chloride) + H2 (HYDROGEN),

Atomic masses: Mg = 24, H = 1, Cl = 35.5

one atom of Mg, 2 atoms of H and 2 atoms of Cl on both sides of the equation,

Law of conservation of mass balance: 24 + 2 × (1+ 35.5) = 24+ (2 × 35.5) + (2×1) = 97 (Both equal 97)

Note the subscript 2 after the Cl in magnesium chloride or the 2 after the H in the hydrogen MOLECULE, means two atoms of that element.

The 2 before the HCl doubles the number of hydrochloric acid molecules.

Right answer is (a) 350 kg, 0.529, 0.471

To ELABORATE: Material Balances (Steady-State, Non-Reactive Process) :

Total Balance: m1 + M2 = m3

Methanol-Balance: m1xM1 + m2xM2 = m3xM3

Water-Balance: m1xw1 + m2xw2 = m3xw3

(choose only 2 equations since one of them is no longer independent)

Physical Constraint (applied to mixture 3):

xM3 + xW3 = 1.00

Always START with the equation with the least NUMBER of unknowns if possible and minimize solving equations simultaneously.

Total Balance (m3)

↓

Methanol Balance (xM3)

↓

Physical Constraint (xW3)

Total balance:

m3 = (200 kg) + (150 kg)

m3 = 350 kg

CH3OH balance:

(200 kg)(0.40) + (150 kg)(0.70) = (350 g)xM3

xM3= 0.529

Physical constraint:

xW3 = 1.00 – xM3 = 1 – 0.529

xW3 = 0.471.

The correct answer is (d) Continuous process

The explanation is: If all properties of a SYSTEM, such as temperature, pressure, concentration, volume, MASS, etc. do not vary with time, the process is said to be at steady state. Continuous processes MAY be either steady state or transient. It is USUAL to RUN continuous processes as close to steady state as possible; however, unsteady-state conditions will exist during start-up and for some time after any change in operating conditions.

Right option is (a) 437 moles/hr, 35 moles/hr, 301.5 moles/hr

To explain I would say: TOTAL NUMBER of moles in the RECYCLE STREAM = 100.50×4/0.92 = 437 moles/hr

Moles of inerts in the recycle stream = 437 – 100.50×4=35 moles/hr

Moles of hydrogen in the recycle stream = 100.50×3 = 301.50 moles/hr.

Right choice is (c) 40 %

Easiest explanation: The process involves TWO reactions:

R1 = C + O2 = CO2

R2 = C + 1/2 O2 = CO

As the product (output) gas composition is specified more clearly, we may USE it as starting point.

TAKE N2 in the product as nN2 = Take N2 in the product as, then O2 = 1 mol

N2 as an inert gas: input = output = 7.18 mol

O2 input with AIR = 7.18 (21/79) = 1.91 mol

Total O2 consumption = 1.91-1 = 0.91 mol

If R1 uses n1 mol O2, generating n1 mol CO2, R2 uses 0.91-n1 mol O2, generating 2

(0.91-n1) mol CO.

Since CO/CO2 in the product gas = 2, 2 (0.91-n1)/n1 = 2

n1 = 0.91/2 = 0.455 mol

Therefore, total moles of C input = 3 n1 = 1.365 mol

O2 required for COMPLETE combustion of 1.365 mol C = 1.365 mol (for R1 only)

O2 excess % = (1.91 -1365)/1.365 x 100% = 39.9% = 40% .

Right answer is (c) Mass

To elaborate: THERMODYNAMIC properties are divided into two BROAD types: intensive properties and EXTENSIVE properties. An extensive property is any property that depends on the size (or extent) of the system under consideration. An intensive property is a bulk property, meaning that it is a physical property of a system that does not DEPEND on the system size or the amount of material in the system. Mass and volume are extensive properties.

Right answer is (c) 16.7%, 22.1%, 0.058, 3.77 moles in m^3

To explain I would SAY: (i) Weight fraction:

20/(100+20) = 0.167; %weight/weight = 16.7%

(II) Weight/volume:

A DENSITY of 1323kg/m^3 means that lm^3 of solution weighs 1323kg, but 1323kg of salt solution CONTAINS

(20×1323kg of salt) / (100+20) = 220.5 kg salt/m^3

1 m^3 solution contains 220.5 kg salt.

Weight/volume fraction = 220.5 / 1000 = 0.2205

And so weight / volume = 22.1%

(III) Moles of water = 100 / 18 = 5.56

Moles of salt = 20 / 58.5 = 0.34

Mole fraction of salt = 0.34 / (5.56 + 0.34) = 0.058

(iv) The molar concentration (M) is 220.5/58.5 = 3.77 moles in m^3.

Right choice is (c) 100%, 75%

Explanation: Overall conversion: Based on the streams that enter and LEAVE the overall process.

Overall conversion =(moles of reactants in FRESH feed-moles in the output of the overall process)/(moles of reactant in fresh feed)

Therefore, the overall conversion of A is from equation:

Overall conversion = ((75 mol A/min)in –(0 mol/min)out)/((75 mol A/min)out) × 100% = 100%

Single-pass conversion: Based on streams that enter and leave the reactor.

Overall conversion = (moles of the reactants FED into the reactor-moles that exiting the reactor)/(moles of reactant fed into reactor)

Therefore, the single-pass conversion from equation is:

((100 mol A/min)in-(25 mol A/min)out)/((100 mol A/min)in) × 100% = 75%.

Right answer is (B) The two STREAMS split with equal composition

Easy EXPLANATION: Splitting POINT: 6 variables – 2 mass balances – 1 knowing compositions are the same – 1 splitting ratio = 2 DOF (Degree of freedom). The splitting point is SPECIAL because when a stream is split, it generally is split into two streams with equal composition.

The CORRECT option is (b) Fed-Batch process

The best I can EXPLAIN: In fed-batch process, nothing is removed from the reactor during the process, but one SUBSTRATE component is added in order to control the reaction RATE by its CONCENTRATION. In a fed-batch process, a basal medium supports initial growth and production, and a feed medium prevents depletion of nutrients and sustains the production phase.

The correct choice is (d) Coefficient of linear expansion

To explain: Thermostat is used in electric apparatus LIKE a refrigerator, Iron etc for automatic CUT off. THEREFORE for metallic STRIPS to BEND on heating their coefficient of linear expansion should be different.

The correct answer is (a) 125 moles/hr, 100.50 moles

The best I can EXPLAIN: Moles of NITROGEN ENTERING the reactor = (37.50/2)/0.15 = 125 moles/hr

Therefore there are 125 – 24.50 = 100.50 moles of nitrogen in the recycle stream.

Right CHOICE is (c) 37.50 moles/hr

To EXPLAIN I would say: The concentration of inerts in the PURGE stream is 8 mole percent. The amount of inerts must be 2 moles/hr in order to PREVENT accumulation of inerts. Therefore the flow rate of purge stream is 25 moles/hr.

The flow rate of NITROGEN and hydrogen in the purge stream is 23 moles/hr (5.75 nitrogen, 17.25 hydrogen). Therefore moles of ammonia produced:

(24.50 – 5.75) x 2 = 37.50 moles/hr of ammonia.

The correct option is (b) 1.066 bars

Easiest EXPLANATION: 1 mm HG = 133.322 Pa and 1 BAR = 10^5 Pa

Therefore,

bars = 800 mm Hg × \(\FRAC{133.322 \,Pa}{1 \,mm \,Hg} × \frac{1 \,bar}{10^5 \,Pa}\) = 1.066 bar.

Right option is (b) False

For explanation: The flow through a pipe at a CONSTANT VELOCITY, clearly there is flow of MATTER and so it is not in thermodynamic EQUILIBRIUM, however since the velocity does not change with time it is in a steady state.

The correct choice is (b) DECREASED reactant CONVERSION

The explanation is: The most COMMON application of recycle for systems INVOLVING chemical reaction is the recycle of reactants, an application that is USED to increase the overall conversion in a reactor and not the decreased reactant conversion.