Organic Chemistry Experiments: Melting Point, Recrystallization, Distillation, Extraction, Tollens' Test, TLC, Column Chromatography, Cyclohexene Synthesis

What is melting point?

The temperature at which a solid becomes a liquid.

How can you determine if a substance is pure or impure?

By observing the temperature range of melting; a pure substance has a melting point range of less than 1°C.

How do intermolecular forces and symmetry affect melting point?

Stronger intermolecular forces and greater symmetry typically lead to higher melting points.

What is recrystallization?

A purification technique used to remove impurities from compounds by dissolving them in hot solvent and allowing them to crystallize.

What is the effect of using too much solvent in recrystallization?

It decreases the recovery of crystals.

How does cooling rate affect crystal size and purity?

Fast cooling results in smaller crystals with lower purity.

How do you calculate percent recovery in recrystallization?

Percent recovery = (recovered mass / initial mass) × 100%.

What is distillation?

A separation technique based on differences in boiling points of substances.

What is the difference between simple and fractional distillation?

Simple distillation is used for substances with boiling points greater than 25°C and provides moderate purity, while fractional distillation is used for substances with similar boiling points and provides high purity.

What are the types of extraction?

Liquid-liquid extraction involves two immiscible liquids, while solid-liquid extraction involves extracting solid material into a liquid.

What is the classification of extraction based on the solvent used?

Aqueous extraction uses water, acid extraction uses dilute acid, and base extraction uses dilute base.

What are the phases for benzoic acid and biphenyl during extraction?

Benzoic acid is typically in the aqueous phase, while biphenyl is in the organic phase.

What is the role of the separatory funnel in extraction?

It is used to separate the organic and aqueous phases based on density.

What is the difference between aldehydes and ketones?

Aldehydes have a carbonyl group at the end of the carbon chain, while ketones have it within the chain.

Which compound gives a positive Tollens's test?

Aldehydes give a positive Tollens's test, while ketones do not.

What happens during the Tollens's test?

Aldehydes are oxidized while Tollens reagent is reduced.

What does TLC stand for?

Thin Layer Chromatography.

How do you calculate the R_f value in TLC?

R_f = distance of the spot / distance of the solvent front.

What is column chromatography?

A technique that uses a column filled with adsorbent to separate compounds based on their affinity for the stationary phase.

What is the E1 reaction in organic chemistry?

A type of elimination reaction that involves the formation of a carbocation intermediate.

What strong acid is required in the conversion of cyclohexanol to cyclohexene?

A strong acid such as sulfuric acid is required.

What are the products formed in the conversion of cyclohexanol to cyclohexene?

Cyclohexene and water (H₂O) are the products.

What comes out first, biphenyl or benzoic acid

Biphenyl, which is the organic phase

What type of reaction is cyclohexene and cyclohexanol

e1