Hello guys i am Murli Pandey and today i am standing here to talk about some chemical properties of metals and non metals.
At a glance
1 - Most metals and some non metals react with oxygen this can be undesirable in our daily lives.
2 - some metals and non metals can react aggressively with water.
3 - some metals are more reactive than other metals.
Think and reflect
Old windows grills or the seesaws and swings in your playground have a reddish brown coating on their metalic parts . Was it always there ? Where does that come from?
Activity I
You will need - paper clip, bolts ,coins, an empty container,
Steps ;
1 - take one of each object and place them in the container
With water , and check them everyday for a few days .
2 - leave the rest of the objects in the dry container to compare what happens .
What was your observation ? What was the difference between the objects in water as compared to the objects in a dry place ? Do they feel different ?
Similarly, copper and silver also react with substances in the air . Copper gets a greenish coating and silver gets a blackish coating . The greenish coating is a mixture of copper hydroxide and copper carbonate the blackish coating is due to the formation of silver sulphide .
A thing to remember
Pure metals like iron , copper and silver get damaged when exposed to air and moisture .
Think and reflect
You would never ever find sodium and potassium freely lying around in nature in nature in their pure form . Why would that be ?
As you can see , such reactions reduce the usability of these materials .
They look pretty bad , don't they ?
If you put sodium in water you will find that it reacts explosively . Potassium quickly catches fire and start bouncing around .
Metals like sodium and potassium are extremely reactive .
They react if left free in air , or if put into water , and with many other substances . This is why you would never find them lying around freely in nature.
Chemical properties of metals and non metals
Chemical property is the characteristic shown by a material during a chemical reaction .
Metals are very reactive and easily form compound with other elements like oxygen , water ,etc .
Reaction with oxygen
We have seen iron getting rusted.rust is iron oxide formed by a redox reaction of iron and oxygen in the presence of water.
Iron is the reducing agent , as it gives up electrons , while oxygen is the oxidising agent gaining electrons .
Let us check the nature of rust formed as a result of reaction between iron, Oxygen and water.
Collect some rust in a small amount of water, you will find that the rust remains suspended in water.
Test the solution with red and blue litmus papers.
What do you observe ?
Is the solution acidic or basic ?
Do you know ?
Iron when exposed to moist air acquires a coating of brown flaky substance called rust .
Silver articles become black after exposing to air.
It happens because it reacts with Sulphur in the air to form a coating of silver sulphate.
Copper reacts with moist carbon dioxide in the air and slowly loses its shiny brown surface and gains a green coat called copper carbonate.
Try to burn magnesium ribbon in air. when magnesium ribbon burns in air it forms an oxide.
Since it combines with Oxygen gas which is O 2 we really need to write both the oxides are basic in nature so metals when burnt in oxygen form basic oxides.
Activity
Aim - To observe the reaction of metals with bases.
Method - Hold a clean magnesium ribbon with a pair of tongs, burn it over a flame.
What do you observe ?
Magnesium ribbon burns with dazzling white flames and gets converted into a white solid residue.
The ash formed is magnesium oxide.
Collect this residual solid ash in a glass Tumbler and add water to it and stir the mixture.
What is the nature of magnesium oxide, is it a acidic or basic?
Observation
To test this, introduce a strip of each red and blue litmus paper into the solution.
You will notice that blue litmus remains unaffected and the red litmus changes to blue.
This indicates that solution is alkaline or basic .
Thank-you
For Reading my blog.
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