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 3 of 4
- A. Rinsing the burette with distilled water instead of the titrant
- B. Reading the burette at the top of the meniscus
- C. Adding too much indicator
- D. Using a dry conical flask
Explanation: Rinsing with water dilutes the titrant, requiring more volume to reach the endpoint, thus overestimating the analyte concentration.
Correct answer: Rinsing the burette with distilled water instead of the titrant- A. To increase the yield of crystals
- B. To prevent decomposition of the compound
- C. To ensure rapid cooling
- D. To maximize solubility of impurities
Explanation: Using a minimum amount of hot solvent keeps the solution saturated, maximizing crystal yield upon cooling while impurities remain dissolved.
Correct answer: To increase the yield of crystals- A. Concentration of HCl
- B. Surface area of marble chips
- C. Temperature of the reaction
- D. Volume of the reaction flask
Explanation: The flask's volume does not affect the reaction rate, which depends on concentration, surface area, and temperature.
Correct answer: Volume of the reaction flask- A. To increase the boiling point
- B. To prevent superheating and ensure smooth boiling
- C. To enhance the separation efficiency
- D. To reduce the distillation time
Explanation: Anti-bumping granules provide nucleation sites, preventing superheating and ensuring smooth boiling during distillation.
Correct answer: To prevent superheating and ensure smooth boiling- A. Buchner funnel
- B. Buchner flask connected to suction
- C. Rubber tubing
- D. Porous plate
Explanation: The Buchner funnel, when used with a vacuum flask, allows rapid filtration under suction.
Correct answer: Buchner funnel- A. If the stem of the funnel is large so that it dips into the filtrate
- B. If the paper covers the funnel up to its circumference
- C. If the paper fits tightly
- D. If the paper has got small sized pores in it
Explanation: During filtration, a tight-fitting filter paper prevents the liquid from bypassing the paper around the edges.
Correct answer: If the paper fits tightly- 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. Dispose of chemicals in proper places and follow posted procedures without returning them to their original containers.
Explanation: Dispose of chemicals in proper places and follow posted procedures without returning them to their original containers.
Correct answer: Dispose of chemicals in proper places and follow posted procedures without returning them to their original containers.- A. Residue
- B. Filtrate
- C. Precipitate
- D. Suspension
Explanation: The clear liquid that passes through filter paper is the filtrate, containing the dissolved components.
Correct answer: Filtrate- A. Continue boiling till dryness
- B. Add more solute
- C. Cool solution slowly
- D. Add cold water
Explanation: Once saturation is reached, gentle cooling allows crystals to form gradually with high purity.
Correct answer: Cool solution slowly- A. Sand
- B. Water
- C. Ammonium chloride
- D. Sodium chloride
Explanation: Ammonium chloride sublimes on heating and re-solidifies on a cold surface.
Correct answer: Ammonium chloride- A. Upper layer
- B. Lower layer
- C. Both layers
- D. Neither
Explanation: Chloroform (denser) forms the lower layer; solute distributes there due to higher solubility.
Correct answer: Lower layer- A. A
- B. B
- C. Both
- D. Cannot determine
Explanation: The farther the spot travels, the greater is its solubility in the solvent.
Correct answer: B- A. 10 mL
- B. 25 mL
- C. 37 mL
- D. 46 mL
- E. 51 mL
Explanation: The theoretical yield at STP can be found from the chemical equation of the reaction: 0.040 g Mg = x L Mg + 2HCL → MgCl2 + H2 (g) 24.0…
Correct answer: 37 mL- A. 730 mm Hg
- B. 727 mm Hg
- C. 30.0 mm Hg
- D. 697 mm Hg
- E. 760 mm Hg
Explanation: Correcting the previous pressure by subtracting the given amount for the vapor pressure of water at 302 K gives you: 727 mm Hg - 30 mm Hg…
Correct answer: 697 mm Hg- A. Around the thermometer
- B. In the condenser
- C. In the circulating water
- D. In the heated flask
- E. In the distillate
Explanation: Since the dissolved ammonia is volatile below the boiling point of water, it will be found in the distillate.
Correct answer: In the distillate- A. FILTER HOT SOLUTION
- B. Avoid premature crystallization
- C. )INCREASE Rate of crystallization
- D. decrease the size
Explanation: The correct option here is (A) FILTER HOT SOLUTIONS.Fluted filter paper is primarily used to filter hot solutions or substances.
Correct answer: FILTER HOT SOLUTION- A. solution
- B. amount of insoluble solute
- C. amount of soluble solute
- D. Amount of solvents
Explanation: The size of filter paper is generally selected based on the amount of (a) solution being filtered.Here's why the other options are…
Correct answer: solution- A. vapourization
- B. solvent extractio
- C. filtration
- D. crystallization
Explanation: The correct answer is (d) crystallization.Crystallization: This process involves separating a solid from its hot saturated solution by…
Correct answer: crystallization- A. reducing agent
- B. oxidizing agent
- C. drying agent
- D. coloring agent
Explanation: rying agent in crystallization (option C):CaCl2 and PCl5: These compounds are known for their hygroscopic properties, meaning they have a…
Correct answer: drying agent- A. Filtrate, residue
- B. Dilute solution
- C. Residue
- D. both a &b
Explanation: The solution remaining after the formation of crystals is called Mother liquor (Option A):Mother liquor refers to the solution that…
Correct answer: Filtrate, residue