Description : What are maximum boiling azeotropes? Give one example?
Last Answer : Ans:- A mixture which boils at temp. brighter than the boiling point of its components the mixture is known as maximum boiling azeotropes. Eg- a mixture of HCl and H2O containing 20.2% of HCl by weight.
Description : Elements that exist in two or more distinctly different solid forms are known as: w) azeotropes x) allotropes y) isotopes z) isochores
Last Answer : ANSWER: X -- ALLOTROPES
Description : Solvent used in extractive distillation (A) Changes the relative volatility of the original components (B) Should be of high volatility (C) Should form azeotropes with the original components (D) All (A), (B) and (C)
Last Answer : (A) Changes the relative volatility of the original components
Description : Pick out the wrong statement. (A) The mole fraction of solute is directly proportional to the molality of a 'dilute' solution (B) For a non-reacting binary mixture of ideal gases, the partial ... at all temperature (D) The relative volatility of a binary mixture at the Azeotropic composition is 1
Last Answer : (C) Azeotropes obey Raoult's law at all temperature
Description : A minimum boiling azeotrope is exemplified by (A) Toluene-benzene (B) Acetone-carbon disulphide (C) Water-isobutyl alcohol (D) None of these
Last Answer : (B) Acetone-carbon disulphide
Description : Pick out the system with minimum boiling azeotrope at 1 atm. (A) Benzene-toluene (B) Ethyl alcohol-water (C) Hydrochloric acid-water (D) All (A), (B) and (C)
Last Answer : (B) Ethyl alcohol-water
Description : Flash distillation is suitable for separating the constituents of a binary system, which (A) Form minimum boiling azeotrope (B) Have very wide boiling points (C) Have very close boiling points (D) Form constant boiling azeotrope
Last Answer : (B) Have very wide boiling points
Description : Flash distillation is suitable for the separation of components (A) Having very close boiling points (B) Which form maximum boiling azeotrope (C) Having very wide boiling points (D) Which form minimum boiling azeotrope
Last Answer : (C) Having very wide boiling points
Description : As the difference between the wall temperature and bulk temperature increases, the boiling heat transfer co-efficient (A) Continues to increase (B) Continues to decrease (C) Goes through a minimum (D) Goes through a maximum
Last Answer : (C) Goes through a minimum
Description : Safety aside, for which of the following reasons is alcohol used in preference to mercury in a minimum thermometer? w) Alcohol has a higher boiling point x) Alcohol has a lower freezing point y) Alcohol contracts more uniformly z) Alcohol can be dyed for visibility
Last Answer : ANSWER: X -- ALCOHOL HAS A LOWER FREEZING POINT
Description : Give three differences between evaporation and boiling.
Last Answer : Ans.i) Evaporation occurs at all temperatures while boiling occurs at boiling point. ii) Evaporation is surface phenomenon while boiling occurs throughout the bulk of liquid. iii) Evaporation is slow while boiling is rapid.
Description : Give reasons i) H2O is a liquid but H2S a gas. ii) Ammonia has higher boiling point than phosphine ii) Krypton & xenon make compounds.
Last Answer : Ans: i) Hydrogen bond is found in H2O but not in H2S. ii) Hydrogen bond is found in NH3 but not in PH3. iii) Because they have low ionization energy.
Description : Give reason .the melting point and boiling point of alkali metals are low
Last Answer : The melting and boiling points of the alkali metals are low indicating weak metallic bonding due to the presence of only a single valence electron in them.
Description : Give reason for the higher melting point and boiling point of alkali earth metals than alkali metals.
Last Answer : The melting and boiling points of these metals are higher than the corresponding alkali metals due to smaller sizes.
Description : Which of the following binary systems is an example of a maximum boiling azeotrope? (A) Water-hydrochloric acid (B) Acetone-carbon disulphide (C) Water-ethyl alcohol (D) n-heptane-n-octane
Last Answer : (A) Water-hydrochloric acid
Description : Boiling of milk in an open vessel is an example of __________ boiling. (A) Film (B) Sub-cooled (C) Saturated nucleate (D) None of these
Last Answer : (A) Film
Description : The boiling of water into steam in an open container is an example of a/an _________ process. a. adiabatic b. isochoric c. isobaric d. zero work
Last Answer : isobaric