Hello candidate,

1. When 2-Bromo Propane undergoes dehydrohalogenation, action involves the removal of halogen and hydrogen group with the addition of a double bond which gives rise to the product as Pentene.

2. When Methyl Bromide reacts with potassium cyanide, then a simple substitution reaction happens which gives the product as methyl cyanide.

Hope this information was informational!