Skip to main content
Sign in Register
Sarkari MCQs Government Exam Question Bank
Question no. 10678

Increasing the quantity of live steam injected during steam distillation affects the distillation temperature by__________________?

Select your answer for: Increasing the quantity of live steam injected during steam distillation affects the distillation temperature by__________________?
Show answer

Answer: B. Decreases

Explanation

Injecting live steam increases the total vapor pressure contribution from the added water steam component. Dalton law dictates that individual partial pressures must sum to the total operating pressure. Higher steam partial pressure reduces the required organic component partial pressure, lowering boiling temperature. Steam distillation enables high boiling point compounds to vaporize at much lower, safer temperatures. Immiscible organic compounds exert independent vapor pressures when mixed together with liquid water. Lowering operational temperatures prevents thermal decomposition of delicate heat sensitive chemical products.

Essential oil extraction industries rely extensively on steam distillation to preserve natural fragrances. Petroleum refineries use steam stripping to separate heavy hydrocarbon fractions without thermal cracking. Chemical synthesis plants purify high boiling intermediates safely by avoiding excessive reboiler temperatures. Temperature decreases rather than increases because added steam depresses the boiling point of the mixture. Assuming temperatures remain unchanged ignores the fundamental vapor pressure lowering effect of added steam. Relative volatility influences separation sharpness rather than directly dictating the steam distillation temperature drop.

Subject
Engineering
Category
Chemical Engineering
Topic
—
Difficulty
medium

Related questions

Engineering Chemical Engineering
medium

Q1. When does the HETP numerically equal the HTU in a separation column______________________?

Select your answer for: When does the HETP numerically equal the HTU in a separation column______________________?
Save
Show answer

Answer: C. And equilibrium lines are parallel

Parallel operating and equilibrium lines maintain a constant driving force throughout the separation section. Constant driving force eliminates the curvature effects that typically separate plate height from transfer uni...

Engineering Chemical Engineering
medium

Q2. Humid volume represents the total volume in m3 of 1 kg of _____________________?

Select your answer for: Humid volume represents the total volume in m3 of 1 kg of _____________________?
Save
Show answer

Answer: C. Gas plus its accompanying vapour at 1 atm. and gas temperature

Humid volume includes the specific volume of dry gas plus its accompanying vapor at system conditions. Specifying one atmosphere and the actual gas temperature ensures accurate volumetric flow calculations. Including vap...

Engineering Chemical Engineering
medium

Q3. If the dry-basis moisture content of a solid is designated as X, what is its corresponding wet-basis moisture content____________________?

Select your answer for: If the dry-basis moisture content of a solid is designated as X, what is its corresponding wet-basis moisture content____________________?
Save
Show answer

Answer: A. X/(X + 1)

Dry basis moisture content relates to total mass excluding moisture, whereas wet basis includes it. Algebraic rearrangement of mass fractions yields the exact transformation formula X divided by X plus one. Consistent mo...

Engineering Chemical Engineering
medium

Q4. Humidity charts assist in evaluating condensation, vaporization, and psychrometric processes. At a specified dry-bulb temperature, the humidity value retrieved directly from the chart corresponds to _______________ humidity?

Select your answer for: Humidity charts assist in evaluating condensation, vaporization, and psychrometric processes. At a specified dry-bulb temperature, the humidity value retrieved directly from the chart corresponds to _______________ humidity?
Save
Show answer

Answer: A. Molal

Standard psychrometric charts plot humidity on axes using molal units for engineering convenience. Moles of vapor per mole of dry gas provide direct inputs for stoichiometric mass balances. Direct reading from the chart...

Engineering Chemical Engineering
medium

Q5. What technique is well-suited for the economical separation of heat-sensitive materials possessing exceptionally high latent heats of vaporization__________________?

Select your answer for: What technique is well-suited for the economical separation of heat-sensitive materials possessing exceptionally high latent heats of vaporization__________________?
Save
Show answer

Answer: A. Liquid extraction

Liquid extraction avoids boiling the mixture, preventing thermal degradation of heat sensitive materials. High latent heats of vaporization make distillation economically prohibitive due to massive energy requirements. T...

Engineering Chemical Engineering
medium

Q6. When overall plate efficiency equals Murphree plate efficiency, both the operating and equilibrium lines must be_______________?

Select your answer for: When overall plate efficiency equals Murphree plate efficiency, both the operating and equilibrium lines must be_______________?
Save
Show answer

Answer: C. Both A. & B.

Straight operating and equilibrium lines ensure constant local mass transfer efficiency across the tray. Parallel lines maintain a uniform concentration driving force from the bottom to the top of the column. Mathematica...