Question

Magnesium. aluminium, zinc and iron were put in different test tubes containing dilute
hydrochloric acid. In which test tube will the rate of formation of bubbles of hydrogen gas be
fastest and why?​

Answer 1

Answer:

Given:-

Magnesium. aluminium, zinc and iron were put in different test tubes containing dilute hydrochloric acid.

To find:-

The fastest rate of reactivity of the following metals.

Let's Learn!

Do you reckon the reactivity series? A brief note here :-

K Pottasiun

Na Sodium

Ca Calcium

Mg Magnesium

Al Alumunium

Zn Zinc

Fe Iron

Sn Tin

Pb Lead

H Hydrogen

Cu Copper

Au Silver

Ag Gold

Pt Platinum

Now, if we move according to the table, the highest reacting metal is Magnesium.

So, Formation of bubbles is fast because it is highly reactive and also, produces bubbles of Hydrogen.

Remember:-

Magnesium does not react with cold water but with hot water, it reacts.

Answer 2

First we will show all reaction's required here :

⑴ When Magnesium react with dilute HCl,

\begin{gathered}\begin{gathered}{\Large\mid}\:\bf{Mg\:+\:2\:HCl\:\longrightarrow\:MgCl_2\:+\:H_2\:}\:{\Large\mid}\ \\ \end{gathered} \end{gathered}∣Mg+2HCl⟶MgCl2+H2∣ 

⑵ When Aluminium react with dilute HCl,

\begin{gathered}\bigstar\:{\Large\mid}\:\tt{2\:Al\:+\:6\:HCl\:\longrightarrow\:2\:AlCl_3\:+\:3\:H_2\:}\:{\Large\mid}

⑶ When Zinc react with dilute HCl,

\begin{gathered}\begin{gathered}\\{\Large\mid}\:\tt{Zn\:+\:2\:HCl\:\longrightarrow\:ZnCl_2\:+\:H_2\:}\:{\Large\mid}\ \\ \end{gathered}\end{gathered}∣Zn+2HCl⟶ZnCl2+H2∣ 

⑷ When Iron react with dilute HCl,

\begin{gathered}\begin{gathered}\\:{\Large\mid}\:\tt{2\:Fe\:+\:6\:HCl\:\longrightarrow\:2\:FeCl_3\:+\:3\:H_2\:}\:{\Large\mid}\ \\ \end{gathered}\end{gathered}:∣2Fe+6HCl⟶2FeCl3+3H2∣ 

☛ Here all metal gives bubble of hydrogen gas.

☛ As we know that in reactive series Mg is present in top, then Al, then Zn and then Fe.

Arrangement of reactive metals given as,

✯ Mg > Al > Zn > Fe

Thus,

★ Mg is most reactive metal and it's rate of formation of bubbles of hydrogen gas be fastest.

Therefore,

\red\checkmark✓ The rate of formation of bubbles of hydrogen gas is fastest in case of reaction of magnesium with dilute HCl.✓✓TherateofformationofbubblesofhydrogengasisfastestincaseofreactionofmagnesiumwithdiluteHCl.