QUIZZES

• What is the primary purpose of using activated charcoal in the decolorization process of brown sugar during recrystallization?

  To remove colored impurities from the sugar solution
• The liquid that passes through the filter paper during filtration is called the

  filtrate
• What is the primary purpose of decolorization in wastewater treatment?

  to remove color compound
• when sand is allowed to settle to the bottom of a beaker filled with water. Sand forms a _________.

  sediment
• Which of the following substances can undergo sublimation under normal conditions?

  A.)Starch

  B) Naphthalene

  C) Both starch and naphthalene

  D) Neither starch nor naphthalene

  Napthalene
• hich of the following substances is most likely to undergo effective recrystallization from water at room temperature? YSE CAPITAL LETTER ONLY

  A.)Benzoic acid

  B) Sodium chloride

  C) Methylene blue

  D) None of the above

  Benzoic Acid
• During simple distillation of a mixture of acetone (boiling point 56°C) and water (boiling point 100°C), which compound will distill first?

  A.)Water

  B) Acetone

  C) Both will distill at the same time

  D) Neither will distill

  Acetone
• What is the primary purpose of performing simple distillation on a mixture of acetone and water?

  A.)To separate acetone from water based on their solubility

  B) To purify water by removing acetone

  C) To separate acetone and water based on their boiling points

  D) To chemically react acetone and water to form a new compound

  To separate acetone and water based on their boiling points
• What is the purpose of adding glacial acetic acid after treating the distillate with sodium nitroprusside and sodium hydroxide?

  A.)To neutralize the reaction

  B) To intensify the color change

  C) To dissolve sodium hydroxide

  D) To precipitate acetone

  To intensify the color change
• During the decolorization of brown sugar with activated charcoal, which of the following steps is most important for effective purification?

  A.)Adding activated charcoal after the solution has cooled

  B) Stirring the solution with activated charcoal while it is hot

  C) Filtering out the activated charcoal before dissolving the sugar

  D) Using cold water to dissolve the sugar

  Stirring the solution with activated charcoal while it is hot
• technique would best be used to separate soil and water?

  filtration
• Which functional group is primarily responsible for the positive result in the sodium nitroprusside test when acetone is present in the distillate?

  A.)Aldehyde

  B) Hydroxyl group

  C) Ketone

  D) Carboxyl group

  Ketone
• What would happen if the temperature during simple distillation more than 56 degrees or exceeds 100°C when separating acetone from water?

  A.)Only acetone will distill

  B) Only water will distill

  C) Both acetone and water will distill

  D) No distillation will occur

  Both acetone and water will distill
• In chemistry, what substance is commonly used for decolorization in a laboratory setting?

  ACTIVATED CARBON

  HYDROCHLORIC ACID

  SODIUM CHLORIDE

  ETHANOL

  activated carbon
• Which of the following is the most appropriate solvent for recrystallizing benzoic acid? USE CAPITAL LETTER

  B.)Cold water

  B) Hot water

  C) Acetone

  D) Ethanol

  Hot water
• he crude product is simply dissolved into solution, and then the conditions are changed to allow crystals to re-form.

  CRYSTALLIZATION

  RECRYSTALLIZATION

  SUBLIMATION

  DECOLORIZATION

  Recrystallization
• When a distillate containing acetone is treated with sodium nitroprusside and sodium hydroxide, what color change would you expect to observe if acetone is present?

  A.)No color change

  B) Blue color

  C) Yellow color

  D) Purple or violet color

  Purple or violet color
• To separate a mixture of salt and water what separation method is used?

  FILTRATION

  DISTILLATION

  CHROMATOGRAPHY

  EVAPORATION

  Evaporation
• During a recrystallization procedure, why is sodium chloride generally not used for recrystallization purification techniques? USE CAPITAL LETTER

  A.)It decomposes upon heating.

  B) It is highly soluble in both hot and cold water.

  C) It forms complex ions during crystallization.

  D) It reacts with methylene blue.

  It is highly soluble in both hot and cold water
• In thin-layer chromatography (TLC), what is the stationary phase?

  solid absobrent on a plate
• What role does hexane play in the TLC analysis of malunggay extract?

  It is the solvent used in the mobile phase
• Which of the following is NOT a commonly used phase in chromatography?

  solid phase
• What type of compounds would be primarily extracted using methanol from malunggay leaves?

  Alkaloids, phenolics, and flavonoids
• What color is typically observed when amino acids react with ninhydrin?

  blue or purple
• Which technique is suitable for separating different pigments in a mixture of dyes or ink?

  chromatography
• In paper chromatography, the MOST soluble solute

  travels furthest away from the start point
• What method is effective for separating a solid from a liquid mixture when the solid does not dissolve in the liquid?

  decantation
• Why is ninhydrin solution sprayed on the chromatogram after the separation of amino acids?

  To visualize the amino acids by causing them to develop a color
• Find the Rf value if y (start line-solvent front) is 10cm and the x (start line-spot) is 5cm.

  0.5
• If a substance is not attracted to the water what happens to the 'dot'?

  dot does not move at all
• In TLC, which phase is typically composed of silica gel?

  stationary phase
• Why must the base line be drawn in pencil and not pen?

  pencil is insoluble with water
• In a sequential extraction process of malunggay leaves, which solvent is typically used first?

  Hexane
• Which amino acid in the mixture (glycine, lysine, phenylalanine) would likely move the furthest up the chromatography paper when using 95% ethanol as the solvent?

  Phenylalanine
• What does the Rf value represent in thin-layer chromatography?

  The ratio of the distance traveled by a compound to the distance traveled by the solvent
• What is the main purpose of using hexane in the extraction of malunggay leaves?

  extract non-polar compounds
• Which of the following is a reason for using methanol in the extraction of malunggay leaves?

  extract polar compounds
• Why is it important to perform the extraction using both hexane and methanol in the study of malunggay leaves?

  to extract both polar and non-polar
• What is the primary purpose of using paper chromatography in the analysis of amino acids like glycine, lysine, and phenylalanine?

  To separate and identify the amino acids in the mixture
• What is the main purpose of using thin layer chromatography (TLC) in analyzing malunggay extract? 


  To separate and identify the components of the extract