Question

What are the possible changes during chemical reaction?

#Need correct answer.

Answer 1

The possible changes during chemical reaction are as followed :

1. The change in the state .
2. Change in colour
3. Evolution of gas
4. Heat is involved .

Answer 2

☆ Ello ☆


following are the possible change during the chemical reaction :-


1 ) change in colour :-

for example:- rusting of iron

tarnishing of silver ( formation of silver sulphide { H2S } which is black in colour ) .






2 ) formation of precipitate :-

potassium iodide and lead nitrate react to form potassium nitrate and lead iodide

that is white ( yellow ) in colour .



KI + Pb( NO3 )2 ====> KNo3 + PbI2





3 ) evolution of gas :-


when the zinc react with dilute hydrochloric acid it involve hydrogen gas


Zn + HCl ===> Zncl2 + H2 .



4 ) change in a state


for example :-

hydrogen reacts with oxygen to give water


H2 ( g ) + O2 (g ) ===> H20 ( l )

here gas a stand for :-( g )

liquid stand for :- ( l )


and solid stand for :-( S )



5 ) change in temperature :-


change in temperature is either exothermic or endothermic



the reaction in which heat are involved is known as endothermic reaction



the reaction in which heat are release is known as exothermic reaction


for example





Cao + H20 ====> Ca( OH )2 + Heat


quicklime react with water to form slacked lime


⏫

here is example of exothermic reaction






hope it's helped



$thanks \:$