Mg2C3 reacts with water forming propyne gas. C3^4- ions has : — s Block Elements Chemistry Question

💡 Solution & Explanation

Step 1: The allylide ion (C3^4-) is present in magnesium carbide (Mg2C3). Its Lewis structure can be written as [C-C≡C]^4-. Step 2: Analyze the bonds in [C-C≡C]^4-: the single bond consists of 1 sigma bond, and the triple bond consists of 1 sigma bond and 2 pi bonds. Step 3: This gives a total of 2 sigma bonds and 2 pi bonds, making option (a) the correct choice.