Antacids are commonly used for neuralizatlization of excess of acids. Why are metal hydroxides better than sodium hydrogencarbonate? Do these treat the cause of hyperacidity.

Antacids are commonly used for neuralizatlization of excess of acids. Why is sodium hydrogencarbonate, not good antacid ?

Why are cimetidine and 'ranitidine better antacids than sodium hydrogen carbonate or magnesium or aluminium hydroxide?

(i) How will you convert an alkyl halide into a primary amine having one more carbon atom than the alkyl halide used? (ii) Why do AMINES dissolves in mineral acids?

When metal 'X' is treated with sodium hydroxide, a white precipitate (A) is obtained, which is soluble in excess of NaOH to give soluble complex (B). Compound (A) is soluble in dilute HCl to form compound (C). The compound (A) when heated strongly gives (D), which is used to extract metal. Identify ( 'X' ), (A), (B), (C) and (D). Write, suitable equations to support their identities.