Which of the dihalides undergo a double dehydroahalogenation to give an alkyne?

Vicinal dihalides undergo double dehydrohalogenation to give terminal alkyne. How many moles of NaNH_2 are used in the overall reaction?

Vicinal dihalides undergo double dehydrohalogenation to give terminal alkyne. How many moles of NaNH_2 are used in the overall reaction?

Which one a gem-dihalide?

Statement-I: Acetylene is formed when ethylene chloride or ethylidene chloride is heated with alcoholic KOH. Statement-II: Both gem dihalides and vinicinal dihalides on dehydrohalogenation form alkyne.

Which of the following reaction will give an alkyne?

Which of the following reaction will give alkyne ?

Which of the following is a gem dihalide ?