Question

CHEMICAL EQUATIONS AND REACTIONS
CLASS 10 (HOTS)

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CONTENT QUALITY

Answer 1

1 )exothermic reaction is the chemical reactions in which heat produces with product.example -
co2+h2o→c6h12o6 +heat +water.
endhothermic reaction is the chemical reaction in which heat is required to reaction.example.
CA(oh)2→cao +h2o.
2) when water is added with solid calcium oxide,then a product calcium hydroxide will be produces.
CaO +h2o→CA(OH)2.

Answer 2

$\huge\bigstar\underline\mathfrak\red{Question\:Number\:1}$

=>Differentiate between exothermic and endothermic reactions with examples.

$\huge\bigstar\underline\mathfrak\red{Answer}$

=> Exothermic reactions : The type of reactions in which the heat is evolved during reaction.

In these reactions, the sign ( + heat ) is written along with the products.

For example :

★ Burning of natural gas :

CH4 + 2O2 → CO2 + 2H2O + Heat

★ Respiration :

C6H12O6 + 6O2 → 6CO2 + 6H2O + Heat

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» Reason for a reaction for being exothermic :

In the exothermic reactions, the total energy of the reactants is more than that of products. According to law of conversation of energy, it can neither be created nor be destroyed. It remains conserved in any Reaction. So, products are formed and some energy remains unused. This particular energy is evolved in form of heat in the reaction, making it exothermic.

Here,

Energy of reactants = Energy of products + Evolved energy ( heat )

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=> Endothermic reactions : The type of Reactions in which the energy ( heat ) is absorbed during the Reaction.

For example :

★ N2 + O2 + Heat → 2NO

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Conditions of reaction :

Conditions of reaction such as Temperature, pressure or catalyst are written above or below the arrows drawn in between the reactants and products.

For example : Refer to the attachment!

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» Reason for the Reaction for being endothermic :

Energy of the product is more than that of reactants. So they can't react with each other unless, some amount of heat energy is not provided to them. This makes the energy of reactants equal to that of the products. According to law of conversation of energy, the Reaction takes place.

During the Reactions, the temperature of surroundings drops down and surroundings become cool, due to absorption of energy.

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$\huge\bigstar\underline\mathfrak\red{Question\:Number\:2}$

=> What happens when water is added to solid calcium oxide taken in a container. Give the chemical formula for the Reaction.

$\huge\bigstar\underline\mathfrak\red{Answer}$

=> When solid calcium oxide also called quick lime is added in water ( H2O ), it forms calcium hydroxide and evolving heat energy.

Chemical Reaction :

CaO + H2O → Ca(OH)2 + Heat

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