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

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.

Lets learn!

Do you reckon the reactivity series? A breif note here -

k Potassium

Ca calcium

Mg Magnesium

Al aluminum

Zn zinc

Fe Iron

Sn Tin

Pb lead

H Hydrogen

Cu Copper

Ag Siver

Au Gold

Pt Platinium

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

So, Formation of bubbles is fast because it is highely reactive and also,produces bubbles of hydrogen

Remember :-

Magnesium doesn't react with cold water but with hot water, it will react.

Answer 2

$\huge \sf \orange {\underline {\red{\underline {Aɴsᴡᴇʀ \ :- }}}}$

Reactions of metals with acids

Dilute acids react with relatively reactive metals such as magnesium, aluminium, zinc and iron. The products of the reaction are a salt plus hydrogen gas.

metal + acid → salt + hydrogen

Here’s a good way to remember it: MASH (M+A→S+H).

The name of the salt depends on the name of the acid. For example:

magnesium + hydrochloric acid → magnesium chloride + hydrogen

Mg + 2HCl → MgCl2 + H2

zinc + sulfuric acid → zinc sulfate + hydrogen

Zn + H2SO4 → ZnSO4 + H2

In general, the more reactive the metal, the faster the reaction. However, aluminium has a protective oxide layer, so it reacts slowly with acids to begin with.