Question

The reaction of ethyl magnesium bromide with water would give (ethane / methane / propane)?

Answer 1

Hint: Ethyl magnesium bromide is a Grignard Reagent.Grignard reagent has the formula RMgX where X is a halogen, and R is an alkyl or aryl group.

Complete step by step answer:
The structure of ethyl magnesium bromide or Grignard reagent is –

Ethylmagnesium bromide is a Grignard reagent with formula $$C_2{H}_{5}MgBr$$. It is widely used in the laboratory synthesis of many organic compounds.
Grignard reagents are made by adding halogenoalkane to magnesium in a flask having ethoxy – ethane (commonly known as diethyl ether or simply "ether"). The flask has a reflux condenser and the mixture is warmed over a water bath for nearly 20 - 30 minutes. Everything has to be perfectly dry because Grignard reagents react with water.
$\Rightarrow C{H}_{3}C{H}_{2}Br+Mg\stackrel{ethoxyethane}{\to }C{H}_{3}C{H}_{2}MgBr$
It is used as a strong base to remove protons from various substrates such as alkynes –
$\Rightarrow RC\equiv CH+EtMgBr\to RC\equiv CMgBr+EtH$
Ethyl magnesium bromide is a good nucleophile, i.e., it is attracted to electron deficient chemical species.
Grignard reagents react with water to produce alkanes.
$\Rightarrow C{H}_{3}C{H}_{2}MgBr+H2O\to C{H}_{3}C{H}_3+Mg(OH)Br$
The reaction of ethyl magnesium bromide with water will produce ethane. This is a wasteful process.

Additional information:
 The inorganic product of this reaction, $$Mg\left(OH\right)Br$$, is known as a "basic bromide". We can consider it as a sort of half-way stage between magnesium bromide and magnesium hydroxide.

Note:
We should always keep in mind that the Grignard reagent has to be stored in completely dry conditions else the reagent will get converted to their corresponding alkanes.