Principle

Borax (sodium tetraborate, Na2B4O7·10 H2O) hydrolyzes easily. The boric acid which is so formed reacts easily with methanol to form boric trimethyl ester, which is volatile and burns with a green flame. Boric triethylester is only produced in this way when
the reaction is proton catalyzed or if pure boric acid is used.

Advanced courses: This experiment can be regarded as a simple esterification reaction and can be discussed when esterifications or nucleophilic substitutions are discussed in general. The boric triester can be compared to the triesters of glycerol.

Learning objectives

• Methanol can be distinguished from ethanol by the formation of the methyl ester.
• This ester burns with a green flame, while ethanol burns with a pale-blue flame.

Benefits

• Easy teaching and efficient learning by using interactive experimentation PHYWE-Software
• Experiment is part of a complete solution set with experiments for the topic Organic Chemistry matched with international curriculum: all topics are covered