When 1-bromobutane is reacted with sodium methoxide in methanol, a nucleophilic substitution reaction called SN2 Substitution Nucleophilic Bimolecular will occur. The mechanism of this reaction is as follows:1. Sodium methoxide CH3O-Na+ dissociates into a methoxide ion CH3O- and a sodium ion Na+ . The methoxide ion acts as a strong nucleophile.2. The methoxide ion CH3O- attacks the electrophilic carbon atom the one bonded to the bromine in 1-bromobutane from the backside, opposite to the leaving group Br- .3. As the methoxide ion forms a bond with the electrophilic carbon, the carbon-bromine bond starts to break, and the bromide ion Br- is released as a leaving group.4. The product of this reaction is 1-methoxybutane, and the reaction proceeds with inversion of configuration at the electrophilic carbon due to the backside attack of the nucleophile.The overall reaction can be written as:CH3CH2CH2CH2Br + CH3O-Na+ CH3CH2CH2CH2OCH3 + NaBr