Question

Explain The Reactions Of Metals & Non- Metals With {a} Acids {b} Air {c} Water

Answer 1

Answer:

Exercises

1. Why does an athlete breathe faster and deeper than usual ahes

List the similarities and differences between aerobic

Answer 2

Reaction with Acids :-

Step 1 :- Take samples of Iron, Zinc, Copper, Sulphur, Aluminium, Carbon, Magnesium, Iodine in separate test tubes.

Step 2 :- Add 5ml of dilute hydrochloric acid to each ofthe testtubes with the help of a dropper.

Observe the reactions.

If you find no reaction, heat the test tube gently.

If you still see no reaction, then add 5 drops of conc. Hydrochloric acid.

Now bring a burning Match stick near the mouth of the test tube and observe what happens.

We observe that :- A colourless gas comes out from some of the test tubes.

• The burning match stick puts off with a pop sound.

• This sound indicates the presence of hydrogen.

• Thus, we can say that when some metals react with acids, they liberate Hydrogen gas.

The chemical reaction is :-

$\boxed{ \sf Metal + Acid \leadsto Salt + Hydrogen \: gas.}$

Reaction with Oxygen/air :-

Aim: To know the reaction of oxygen with metals and non-metals.

Materials required :- A metal sample magnesium and a non-metal sample sulphur, spirit lamp or Bunsen burner and litmus papers,etc.

Procedure :-

Take a small strip of magnesium and note its appearance. Burn it. Note the appearance after burning.

Collect the ash of magnesium in a test tube and add some distilled water to it.

Test the solution with red and blue litmus papers.

Note the colour change.

We observe that :-

• The red litmus paper turns blue when it is dipped in the solution of water and Magnesium ash indicating the solution is basic in nature.

• Take a small quantity of powdered sulphur in a deflagrating spoon and heat it on a spirit lamp.

• As soon as sulphur starts burning, introduce the spoon into a gasjar/tumbler.

• Be cautious, do not inhale fumes,they are harmful

• Cover the tumbler with a lid to ensure that the gas produced does not escape.

• Remove the spoon after some time but try to keep the jar covered.

• Add a small quantity of water into the tumbler and quicklyreplacethe lid.

• Shake the tumbler well.

At last, Check the solution with red and blue litmus papers.

We observe that :- The blue litmus paper turns red when it is dipped in the solution of water and gas produced in the

jar where sulphur is burnt.

It indicates that this solution is acidic in nature.

When Magnesium and Sulphur are burnt, They react with oxygen in air to give their respective oxides.

$\boxed{ \sf Magnesium _{ (s)} + Oxygen _{ (g)} \leadsto Magnesium \: oxide_{ (s)}}$

$\boxed{ \sf Sulphur_{(s)} + Oxygen_{(g) }→ Sulphur \: dioxide_{(s)}}$

Both the products in the above reactions are oxides.

Do these oxides have same nature?

No.

• The oxide of magnesium turns red litmus to blue. therefore, we can say that magnesium oxide is basic in nature.

• The oxide of sulphur turns blue litmus to red therefore Sulphur dioxide is acidic in nature.

What can we conclude?

• non-metals react with oxygen to give oxides which are acidic in nature.

• metals react with oxygen to give oxides that are basic in nature.

We can conclude that Metal oxides are basic in nature and Non-metal oxides are acidic in nature.

Reaction with water :-

Step 1 :- Take 500 ml beaker or a big glass trough and fill half of it with water.

Step 2 :- Take a piece of sodium metal which is stored in kerosene and keep it on a sheet of filter paper to blot the kerosene.

Step 3 :- Cut a very small piece of sodium fromit.

Step 4 :- Put the remaining sodium back in kerosene.

Standing away from the trough, put the sodium piece in water using forceps.

• The piece of sodium floats on the surface of the water with a 'hissing' sound.

• This shows that sodium is reacting extremely fast with water.

• After the reaction is completed,test the solution with red litmus paper.

We observe that :-

The red litmus paper turns to blue.

• This indicates that the solution is basic and Sodium is a metal.

• Repeat the same experiment using aluminium or iron.

• You will not see any change even after five minutes.

• This is because these metals react extremely slowly with water.

• Some metals react vigorously with water like in case of sodium.

• On the other hand, some metals react very slowly with water like in case of iron.

• Some metals react with water to form metal oxides and metal hydroxides. Hydrogen gas is released in this reaction.

• The hissing sound is produced when hydrogen gas is released from water.

The chemical reactions involved are :-

$\boxed{\sf Sodium + water \leadsto Sodium \: Hydroxide + Hydrogen \: gas.}$

$\boxed{ \sf Magnesium + hot \: water \leadsto Magnesium \: Oxide + Hydrogen \: gas.}$

Do non-metals react with water?

Generally Non-metals do not react with water.