Question

Combination reaction is the reverse of decomposition reaction , justify this statement with the help of appropriate chemical equation of each

Answer 1

Combination reaction is the one in which two or more elements combine to form one single compound under the action of physical factors.
For example:
2H2 + O2 ––––› 2H2O

Decomposition or Decombination reaction is the one in which a compound is broken to form it's constituents molecules or atoms or elements under the action of physical factors.
For example:
2H2O ---electrolysis-------› 2H2 + O2.

Thanks.

Answer 2

Heya!!

Here is your answer.

⭐$Combination\:reaction:-$

✨In a combination reaction, two or more reactants add up to form a product.

$EXAMPLES:$

⭐$The\:burning\:of\:carbon-$

✨If we burn some charcoal (carbon) in a deflagrating spoon, and put the spoon in the mouth of an open gas jar and close the mouth of the jar with a lid and invert it, the limewater rises in the jar and becomes milky. This proves that carbon dioxide has been formed as it is a property of their gas to turn limewater milky.

So, during buring, carbon combined with the oxygen of the air to form carbon dioxide.

$C+O2=>CO2$

⭐$The\:burning\:of\:magnesium-$

✨ Magnesium is a silvery white metal.When it is ignited in the open air, it burns with dazzling white flame. Magnesium oxide, the product, deposits as a white smoky solid on the walls of the jar. Magnesium combines with the oxygen of the air during burning to form the product.

$2Mg+O2=>2MgO$

Now,Why is combination reaction just the opposite of decomposition reaction??

Ans-Read the definition of both.

⭐$Decomposition\:reaction$

✨In a decomposition reaction, one substance breaks down into two or more simpler substances.

$EXAMPLE:-$

⭐$The\:decomposition\:of\:baking\:soda-$

✨Sodium hydrogencarbonate (NaHCO3) is called baking soda. On heating, baking soda decomposes into sodium carbonate, water (vapour) and carbon dioxide.

$2NaHCO3=>Na2CO3+H2O+CO2$

⭐ Hope it's clear⭐