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1. You are purifying an organic reaction using a separatory funnel. The procedur

ID: 541157 • Letter: 1

Question

1. You are purifying an organic reaction using a separatory funnel. The procedure requires you use dichloromethane (density 1.33g/mL) and water (density 1.00g/mL). Two colorless clear layers have formed. Where do you expect to find your neutral non-polar organic product?

Dichloromethane, top layer

Water, top layer

Dichloromethane, bottom layer

Water, bottom layer

2. There are two candidates for the carboxylic acid extracted in the lab: benzoic acid and 2-chlorobenzoic acid. Which one is more acidic (has a lower pKa) and why?

Benzoic acid. More resonance structures.

Benzoic acid. Oxygen well suited to host negative charge.

2-chlorobenzoic acid. More resonance forms than benzoic acid.

2-chlorobenzoic acid. The chloride reduces the electron-density of the conjugate base via the inductive effect.

3. The structures of glucose and acetominophen are shown below. Using water and ethyl acetate (a typical organic solvent), in which layer are you likely to find the compounds?

a. glucose in water

acetaminophen in water

b. glucose in ethyl acetate

acetaminophen in ethyl acetate

c. glucose in water

acetaminophen in ethyl acetate

glucose in ethyl acetate

acetaminophen in water

a.

Dichloromethane, top layer

b.

Water, top layer

c.

Dichloromethane, bottom layer

d.

Water, bottom layer

Explanation / Answer

1)

Less denser liquid is on the top and more denser is in the bottom.

Since dichlormethane is denser than the water, water is the top layer and dichloromethane is the bottom layer.

Since 'like dissolves like", neutral non-polar organic product is soluble in non-polar organic dichloromethane solvent.

Answer: C. Dichloromethane, bottom layer