Which of the following statements related to s n1 reactions is not true? - the heterolysis of a bond between atoms which do not bear formal charges always produces a cation and an anion - the charged carbon atom of a carbocation has a complete octet of valence shell electrons - carbocations are lewis acids - nucleophiles seek centers of low electron density

The charged carbon atom of a carbocation has a complete octet of valence shell electrons

Explanation:

A charged carbon atom of a carbocation has a valence shell that is not filled, that's why it acts as an electrophile (or a Lewis base). This unfilled valence shell is also the reason of the nucleophilic attack that takes place during the second step of a SN1 reaction.

A half-reaction can be written to represent reduction. At the same time the magnesium atoms become ions, the oxygen atoms become –2 anions by gaining one electron each. By combining these two reactions, we have an oxidation reaction and a re- duction reaction, that are perfectly balanced.

Explanation:

Regroup terms.

2Mg+2O=2mgo

Subtract 2Mg2Mg from both sides.

2O=2mgo-2Mg

Factor out the common term 2.

2O=2(mgo-Mg)

Cancel 2 on both sides.

O=mgo−Mg