How many of the reagents from the list above would give effervescence, when treated with propyne?

(I) $N a O H$ (II) $C H_{3} C H_{2} O N a$ (III) $C H_{3} C H_{2} M g B r$
(IV) $N a H$ (V) $N a N H_{2}$ (VI) $N a$
(VII) $N a H C O_{3}$ (VIII) ${(C H_{3})_{2} C H}_{2} N L i$ (IX) $C H_{3} C H_{2} L i$

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Solution

Effervescence is the formation of gas bubbles in a liquid. It is the escape of gas from an aqueous solution by the chemical reaction.
(I) $N a O H$ does not react with propyne since the alkynes are weak acids.
(II) Sodium methoxide $(N a O C H_{3})$ is not a strong enough base to deprotonate the terminal alkyne.
(III) $C H_{3} C H_{2} M g B r + p r o p y n e ⟶ C H_{3} - C \equiv C - M g B r + C_{2} H_{6}$
No gas, hence no effervescence
(IV) $N a H$ reacts with propyne liberating $H_{2}$ . Hence gives effervescence
$N a H + C H_{3} - C \equiv C H ⟶ C H_{3} - C \equiv C N a + H_{2}$
(V) Propyne reacts with $N a N H_{2}$ evolving ammonia.
(VI)Alkynes reacts with Na giving carbanions liberating $H_{2}$ .
(VII) Acids only give brisk effervescence with $N a H C O_{3}$ by evolving $C O_{2}$ from the carboxylic acids.
(VIII)&(IX) Lithium diethylamide is a weaker base than ethyl lithium. Both react with propyne giving no effervescence.
Hence, Answer: $N a H, N a N H_{2}, N a$

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