When the solvent dissolves very little of solute, then

(A) Solvent of low latent heat of vaporisation should be used

(B) Solvent of low freezing point should be used

(C) Large quantity of solvent is required to extract the solute

(D) Very small quantity of solvent is required


1 Answer

Answer :

(C) Large quantity of solvent is required to extract the solute

Related questions

Description : ick out the undesirable property for a good refrigerant. (A) High thermal conductivity (B) Low freezing point (C) Large latent heat of vaporisation (D) High viscosity

Last Answer : (D) High viscosity

Description : The solvent used in liquid extraction should not have high latent heat of vaporisation, because (A) The pressure drop and hence the pumping cost will be very high (B) It cannot ... by distillation may be prohibitively high (D) It will decompose while recovering by distillation

Last Answer : (C) Its recovery cost by distillation may be prohibitively high

Description : The rate of solid-liquid extraction is limited by the (A) Phase change of the solute as it dissolves in the solvent (B) Diffusion of the solute through the solvent in the pores to the outside of the particle (C) ... contact with the particle to the main bulk of the solution (D) All 'a', 'b' & 'c'

Last Answer : (D) All 'a', 'b' & 'c'

Description : On addition of solute in the solvent, the __________ of the solution decreases. (A) Boiling point (B) Freezing point (C) Vapour pressure (D) Both (B) and (C)

Last Answer : (D) Both (B) and (C)

Description : A _____ dissolves in water. a. solvent b. hydrophobic molecule c. solute d. non polar molecule

Last Answer : c. solute

Description : Heat sensitive materials with very high latent heat of vaporisation may be economically separated using (A) Liquid extraction (B) Distillation (C) Evaporation (D) Absorption

Last Answer : (A) Liquid extraction

Description : In a single stage extraction process, 10 kg of pure solvent S (containing no solute A) is mixed with 30 kg of feed F containing A at a mass fraction xf = 0.2. The mixture splits into an extract phase E and a raffinate ... phase is (in Kg) (A) 6.89 (B) 8.89 (C) 10 (D) 8.25

Last Answer : (B) 8.89

Description : Entrainer used in Azeotropic distillation should (A) Form a low boiling azeotrope with one of the constituents of the mixture (B) Form a new azeotrope of low relative volatility with one of the ... (C) Have high latent heat of vaporisation (D) Have high viscosity to provide high tray efficiency

Last Answer : (A) Form a low boiling azeotrope with one of the constituents of the mixture

Description : Clausius-Clapeyron Equation gives accurate result, when the (A) Vapour pressure is relatively low and the temperature does not vary over wide limits (B) Vapour obeys the ideal gas law and the latent heat of ... is negligible compared with that in the vapour state (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : When a solute is dissolved in a pure solvent, the resulting freezing point is: w) higher than pure solvent x) lower than pure solvent y) does not change z) cannot tell from this information

Last Answer : ANSWER: X -- LOWER THAN PURE SOLVENT

Description : It is desired to concentrate a 20% salt solution (20 kg of salt in 100 kg of solution) to a 30% salt solution in an evaporator. Consider a feed of 300 kg/min at 30°C. The boiling point of the solution is 110°C, the latent heat of ... 3.06 10 5 (B) 6.12 10 5 (C) 7.24 10 5 (D) 9.08 10

Last Answer : (A) 3.06 × 10

Description : Gibbs free energy per mole for a pure substance is equal to the (A) Latent heat of vaporisation (B) Chemical potential (C) Molal boiling point (D) Heat capacity

Last Answer : (B) Chemical potential

Description : In distillation column design, the McCabe-Thiele procedure is inadequate and a Ponchan-Savarit procedure is needed, when (A) Saturated feed is not used (B) An azeotrope forms (C) The latent ... vaporisation of the more and less volatile components are greatly different (D) A total condenser is used

Last Answer : (D) A total condenser is used

Description : An equipment which converts the latent or sensible heat of one fluid into the latent heat of vaporisation of another, is called a (A) Boiler (B) Heat exchanger (C) Recuperator (D) Regenerato

Last Answer : (B) Heat exchanger

Description : In a cooling tower, water becomes cool by (A) Loosing sensible heat (B) Heat transfer to surroundings (C) Vaporisation due to heat loss to air (D) Loosing latent heat

Last Answer : (A) Loosing sensible heat

Description : High __________ is an undesirable property for a good refrigerant. (A) Specific heat (B) Latent heat of vaporisation (C) Viscosity (D) Specific vapor volume

Last Answer : (C) Viscosity

Description : The critical pressure at which the latent heat of vaporisation of steam becomes zero is __________ Kg/cm2. (A) 273.15 (B) 225.65 (C) 100.03 (D) 373.15

Last Answer : (B) 225.65

Description : Pick out the wrong statement. (A) 'Solvates' are chemical compounds formed by solute with their solvents. When water is the solvent, then it is called a 'hydrate' (B) In heat exchanger ... vertical evaporators, area of central downtake is about 50 to 100% of the total tube cross-sectional area

Last Answer : (C) Heat transfer co-efficient during nucleate boiling is not influenced by the agitation imparted

Description : Why high latent heat of vaporisation is desirable in a refrigerant ?

Last Answer : A high latent heat of vaporisation of refrigerant results in small amount of refrigerant and thus lesser circulation system of refrigerant for same tonnage.

Description : Steam at 1000C causes more severe burns than water at 100° C because (1) steam has no specific heat capacity (2) steam has latent heat of vaporisation (3) water has no specific heat capacity (4) water has latent heat of fusion

Last Answer :  steam has latent heat of vaporisation

Description : Only small amount of evaporation of water produces large cooling effects because of its (A) Large latent heat (B) Low viscosity (C) Small latent heat (D) None of these

Last Answer : (A) Large latent heat

Description : A good solvent used for absorption should not have very high (A) Viscosity (B) Vapor pressure (C) Freezing point (D) All (A), (B) & (C)

Last Answer : (D) All (A), (B) & (C)

Description : If a student dissolves powdered sugar in a water in a beaker the student then places a strip of silver in the beaker what is the solute in this solution?

Last Answer : Sugar is the solute.

Description : n a chemical factory where dyes are made, wet cake at 30 OC consisting of 60% moisture  is put in a dryer to obtain an output having only 5% moisture, at atmospheric pressure. In  each batch about 120 ... dryer and the dryer efficiency  is 80%. Latent heat of steam at 4 kg/cm2 is 520 kcal/kg.

Last Answer : Given that   Qty of material dried per batch - 120 Kgs  Moisture at inlet - 60% a. The quantity of moisture removed per batch.  Water quantity in a wet batch - 120 x 0.6 = 72 Kgs.  Quantity of bone dry ... - 48/0.95 = 50.5 Kgs.  Equivalent water in a dry batch - 50.5 - 48 = 2.5 Kgs.

Description : The quantity of heat required to raise the temperature of a given substance by 1 oC is known as: a) sensible heat b) specific heat c) heat capacity d) latent heat

Last Answer : specific heat specific heat is the quantity of heat required to raise the temperature of 1 gram substance by 1 oC is

Description : Which of the following is not a desirable property of a refrigerant (a) highmisibility with oil (b) low boiling point (c) good electrical conductor (d) large latent heat

Last Answer : Ans: c

Description : A binary mixture of benzene and cyclohexane is separated by (A) Flash vaporisation (B) Extractive distillation (C) Solvent extraction (D) Ordinary distillation

Last Answer : (B) Extractive distillation

Description : In liquid extraction, if the selectivity is unity, then (A) Separation of the constituents is the most effective (B) No separation will occur (C) Amount of solvent required will be minimum (D) Solvent flow rate should be very low

Last Answer : (B) No separation will occur

Description : Choose the correct statement (a) A refrigerant should have low latent heat (b) If operating temperature of system is low, then refrigerant with low boiling point should be used (c) Pre-cooling and sub-cooling bf refrigerant are same (d) Superheat and sensible heat of a. refrigerant are same

Last Answer : Ans: b

Description : Pick out the wrong statement. (A) The condensing film co-efficient is about 3 times lower for vertical condenser as compared to the equivalent horizontal condenser for identical situation ( ... in a heat exchanger is controlled by the value of the film co-efficient, which is higher

Last Answer : (D) Overall heat transfer co-efficient in a heat exchanger is controlled by the value of the film co-efficient, which is higher

Description : . In a solution containing 0.30 Kg mole of solute and 600 kg of solvent, the molality is (A) 0.50 (B) 0.60 (C) 1 (D) 2

Last Answer : (A) 0.50

Description : Molarity is defined as the number of gm moles of solute per __________ of solvent. (A) Litre (B) kg (C) gm (D) c.c

Last Answer : (A) Litre

Description : The process employing desorption of the absorbed solute by a solvent is called (A) Elution (B) Osmosis (C) Reverse osmosis (D) Sublimation

Last Answer : (A) Elution

Description : With increase in temperature, the rate of leaching increases, because the (A) Diffusivity of solute increases (B) Viscosity of solvent decreases (C) Thermal conductivity of solute increases (D) None of these

Last Answer : (A) Diffusivity of solute increases

Description : Pick out the wrong statement: (A) Change in barometric pressure does not affect the relative humidity (B) In case of a packed tower, the operating velocity is about half of the ... (D) The equilibrium moisture content of the solid can be reduced by increasing the absolute humidity

Last Answer : (D) The equilibrium moisture content of the solid can be reduced by increasing the absolute humidity

Description : The individual mass transfer co-efficients (moles/m2s) for absorption of a solute from a gas mixture into a liquid solvent are, KL = 4.5 and KG = 1.5. The slope of the equilibrium line is 3. Which of ... A) Liquid side (B) Gas side (C) Interfacial (D) Both liquid and gas side

Last Answer : (B) Gas side

Description : Molality is defined as the number of gm moles of solute per __________ of solvent. (A) Litre (B) gm (C) Kg (D) m

Last Answer : (C) Kg

Description : Pick out the wrong statement. (A) Mechanical agitation is required, if the system has low interfacial tension (B) Sieve tray towers are generally used for systems having low ... Prandtl analogy for heat and mass transfer considers the transfer through both laminar and turbulent layers

Last Answer : (A) Mechanical agitation is required, if the system has low interfacial tension

Description : What is defined as the quantity of heat needed to raise the temperature of one kilogram of water by one degrees Celsius?  a. Kilojoule  b. Btu  c. Kilocalorie  d. Latent heat

Last Answer : Kilocalorie

Description : The snow on the mountains does not melt all at once when it is heated by the sun because _____ A. It becomes very hard It B. It reflects most of the heat from the sun C. It has a low specific heat capacity D. It has a high latent heat of fusion

Last Answer : ANSWER: B

Description : The snow on the mountains does NOT melt all at once when it is heated by the sum because: (1) It becomes very hard (2) It reflects most of the heat from the sum (3) it has a low specific heat capacity (4) it has a high latent heat of fusion

Last Answer : (2) It reflects most of the heat from the sum Explanation: Newly formed snow reflects about 90 per cent of the sunlight that falls upon it. This means that the sun is powerless to melt clean snow. And when ... on a spring day because of the sun's heat. It melts because of the warm air from the sea.

Description : The snow on the mountains does NOT melt all at once when it is heated by the sum because: (1) It becomes very hard (2) It reflects most of the heat from the sum (3) it has a low specific heat capacity (4) it has a high latent heat of fusion

Last Answer : (2) It reflects most of the heat from the sum Explanation: Newly formed snow reflects about 90 per cent of the sunlight that falls upon it. This means that the sun is powerless to melt clean snow. And when ... on a spring day because of the sun's heat. It melts because of the warm air from the sea.

Description : The snow on the mountains does NOT melt all at once when it is heated by the sun because: (1) it becomes very hard (2) it reflects most of the heat from the sun (3) it has a low specific heat capacity (4) it has a high latent heat of fusion

Last Answer : it reflects most of the heat from the sun

Description : Which of the following properties is greater for a solution than for the pure solvent? w) freezing point x) vapor pressure y) temperature z) boiling point

Last Answer : ANSWER: D -- BOILING POINT

Description : Solubility of a substance which dissolves with an increase in volume and liberation of heat will be favoured by the (A) Low pressure and high temperature (B) Low pressure and low temperature (C) High pressure and low temperature (D) High pressure and high temperature

Last Answer : (B) Low pressure and low temperature

Description : Transportation of 35% oleum during winter suffers from the problem of freezing, which can be overcome by the addition of small quantity of (A) Nitric acid (B) Hydrochloric acid (C) Methyl alcohol (D) Formic acid

Last Answer : (A) Nitric acid

Description : What is the difference between a solvent and a solute?

Last Answer : Answer: A solvent is a substance that dissolves another substance, called a solute, to form a homogeneous mixture. The solvent is typically present in the greater amount, while the solute is present in the ... in a solution of sugar dissolved in water, water is the solvent and sugar is the solute.