Free Experimental Techniques in Chemistry MCQs with Answers
79 Experimental Techniques in Chemistry MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Separation methods are selected according to differences in solubility, particle size, volatility and sublimation behaviour. Filtration and crystallisation separate insoluble or dissolved solids, sublimation isolates suitable volatile solids, distillation separates liquids by boiling point, and solvent extraction transfers a substance between immiscible solvents.
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Read the Experimental Techniques in Chemistry notesFree MDCAT chapter notes with key terms79 questions · page 4 of 4
- A. Around the thermometer
- B. In the condenser
- C. In the circulating water
- D. In the heated flask
Explanation: Distillation is described as a two-step process: Vaporization → Condensation. For vaporization to happen, you need a heat source.
Correct answer: In the heated flask- A. Around the thermometer
- B. In the condenser
- C. In the circulating water
- D. In the heated flask
Explanation: Distillation is used to separate a volatile liquid (like water) from a non-volatile solid (like magnesium chloride).
Correct answer: In the heated flask- A. Move the flask farther from the flame.
- B. Move the flask closer to the flame.
- C. Allow less air into the collar of the burner.
- D. Allow more air into the collar of the burner.
Explanation: An orange, sooty flame indicates incomplete combustion due to insufficient oxygen.
Correct answer: Allow more air into the collar of the burner.- A. 0.1 M
- B. 0.2 M
- C. 0.3 M
- D. 1 M
Explanation: Using the titration formula M1V1=M2V2 for the acid and base. Plugging in the values gives (0.1 M) (30 mL)= Mbase(15 mL).
Correct answer: 0.2 M- A. Add concentrated acid to water slowly, following the appropriate safety protocols.
- B. Add water to the concentrated acid slowly.
- C. Carefully return unused or excess chemicals to their original containers.
- D. Flush eyes with water at the eyewash fountain for at least 15 minutes, then report the accident for further help.
Explanation: Add concentrated acid to water slowly, following the appropriate safety protocols.
Correct answer: Add concentrated acid to water slowly, following the appropriate safety protocols.- A. The rule is to add concentrated acid to water slowly.
- B. The rule is to add water to the concentrated acid slowly.
- C. Carefully replace unused or excess chemicals into their properly labeled containers from which they came.
- D. Flush eyes with water at the eyewash fountain for at least 15 minutes, and then report the accident for further help.
- E. Dispose of chemicals in the proper places and following posted procedures. Do not return them to their original containers.
Explanation: You never return chemicals or solutions to their original containers for fear of contaminating the original source.
Correct answer: Dispose of chemicals in the proper places and following posted procedures. Do not return them to their original containers.- A. Destructive distillation
- B. Fractional distillation
- C. Vacuum distillation
- D. Partial distillation
Explanation: Destructive distillation is a process that involves heating organic material in the absence of air or oxygen to break it down into simpler…
Correct answer: Fractional distillation- A. Coal tar
- B. Coke
- C. Coal gas
- D. All of above
Explanation: Destructive distillation is a chemical process in which decomposition is achieved by heating to a high temperature; the term generally…
Correct answer: All of above- A. Crystallization
- B. Distillation
- C. Re-distillation
- D. Fractional distillation
Explanation: c) Re-distillation: Re-distillation is essentially the same as distillation.
Correct answer: Re-distillation- A. 290°C
- B. 110°C
- C. 156°C
- D. 210°C
Explanation: Correct option is D. Under vacuum, the boiling temperature of glycerin decreases to 210°C at 50 torr.
Correct answer: 210°C- A. Radial.
- B. Angular.
- C. Insoluble.
- D. Soluble
Explanation: The insoluble solid particles can be separated from the liquid by filtration.
Correct answer: Insoluble.- A. KOH
- B. Gypsum
- C. CaCl2
- D. Silica sand
Explanation: The anhydrous calcium chloride will absorb any water (including condensation, vapour etc) in its environment.
Correct answer: CaCl2- A. Iodine.
- B. Benzoic acid.
- C. Solvent.
- D. Stationery.
Explanation: Solvent extraction is an equilibrium process controlled by distribution law or partition law.
Correct answer: Solvent.- A. Acetic Acid
- B. Oxalic Acid
- C. Benzoic Acid
- D. Citric Acid
Explanation: Explanation:Benzoic acid has a high melting point (122°C) and a low vapor pressure, which allows it to sublime at room temperature and…
Correct answer: Benzoic Acid- A. Ammonium sulphate
- B. Sodium chloride
- C. Benzoic acid
- D. Lead carbonate
Explanation: A is incorrect as ammonium sulphate is purified through centrifuging.B is incorrect as sodium chloride is purified by crystallization.C is…
Correct answer: Benzoic acid- A. Deliquescence
- B. Fluorescence
- C. Phosphorescence
- D. Solvent extraction
Explanation: Solvent extraction is used for separation of mixtures
Correct answer: Solvent extraction- A. Iodine is extracted from CCl4 layer by water
- B. Iodine is extracted from aqueous layer by CCl4
- C. Iodine is more soluble in water than CCl4
- D. The value of K depends on the amount of Iodine added
Explanation: Iodine vastly prefers to dissolve in CCl4 , thus it migrates from the aqueous (H2O) phase into the non-aqueous (CCl4) phase , thus we say…
Correct answer: Iodine is extracted from aqueous layer by CCl4- A. Simple diffusion
- B. Fractional distillation
- C. Chromatography
- D. Graham's law of diffusion
Explanation: Fractional distillation is the special technique which is used for separation of mixture of two gases
Correct answer: Fractional distillation- A. NaHCO3
- B. CaCO3.H2O
- C. CaCl2 anhydrous
- D. Na2SO4.H2O
Explanation: CaCl2 (anhydrous calcium chloride): Calcium chloride is a widely used drying agent due to its strong hygroscopic properties.
Correct answer: CaCl2 anhydrous