Principle


Test the reactivity of heptane and liquid paraffin.The bond energy for C-C bonds (348 kJ mol-1) and C-H bonds (413 kJ mol-1) is relatively high for non-polar bonds (for comparison, Br-Br: 193 kJ mol-1). They are therefore difficult to attack. In addition, by reason of the low polarity, there is no appropriate target for an electrophilic or for a nucleophilic attack. Only very energy-rich radicals can react with alkanes under normal conditions.

The test with potassium permanganate serves here already as an introduction to double bonds (Baeyer test).

What you can learn about


Alkanes are very unreactive. They do not react even with strong acids or oxidizing agents.´

The low reactivity of the alkanes results from the non-polar, and therefore hardly attackable, single bonds.


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