Benzoic Acid Synthesis Worksheet

Which of the following reagents is most commonly used as the oxidizing agent in the synthesis of benzoic acid from ethylbenzene?

• The solution turns bright pink.

• The solution becomes completely colorless.

• Large bubbles of oxygen gas stop forming.

• To dissolve the glassware.

• To protonate the benzoate ion into insoluble benzoic acid so it precipitates.

• To neutralize the water.

• To speed up the oxidation process.

What is the purpose of performing a "Recrystallization" after the crude benzoic acid is collected?

• To increase the total mass of the product.

• To change the chemical formula of the product.

• To remove impurities and obtain pure crystals.

• To turn the solid back into a liquid for storage.

• Ignore it since it’s a small amount and finish the step.

• Immediately remove the gloves, wash your hands, and notify the instructor.

• Wipe it off with a paper towel and keep working.

• Wait until the end of the lab to report it.

When recording your results, you realize your percent yield is over 100%. What is the most honest and professional way to handle this in your report?

• Change the numbers so the yield looks like 90%.

• Report the 100%+ yield and explain that the product is likely still wet or contains impurities.

• Do not report a yield at all.

• Blame the lab equipment for being uncalibrated.

You have two options for reagent to choose in synthesis of benzoic acid:

a. ethylbenzene, C6H5-CH2CH3

b. toluene, C6H5-CH3

Which reagent you will choose and why?