Chemical reaction and equation part -2

Question 1

Write a equation of reaction where green colour substance change it’s colour into brown colour ‘cause of heating

Answer 1

The equation of the following -
2FeSO4—— Fe2O3 + SO2 + SO3
Above the arrow - heat

2FeSO4- Ferrous sulphate
Fe2O3 -Ferric oxide

Question 2

A) Name a substance in which pungent smell (egg rotten smell) will occur.

B)After heating 2FeSO4 what changes occur??

Answer 2

A) SO2

B) *2FeSO4 breaks down into simpler forms -

2FeSO4 —–Fe2O3 + SO2 + SO3

*Also after heating the green colour 2FeSO4 changes into brown colour

Question 3

What will happen when limestone is heated??

Answer 3

When limestone is heated it breaks down into-
CaCO3——-CaO + CO2

Question 4

In this given reaction -
2Pb(NO3)2————-2PbO + 4NO2 + O2

A)Identify the brown fumes and residue giving their chemical names

B) state the type of reaction

Answer 4

A)The brown fumes and residue is Lead oxide

B) Decomposition reaction

Question 5

In this following reaction

2FeSO4 —–Fe2O3+ SO2 + SO3

A)State the colour of Ferrous sulphate before and after heating

B)Name the gas produced

Answer 5

A) before - light green
After- brown
*‘cause after heating Ferrous sulphate changes into Ferric oxide

B)the gas produced are SO2 , SO3

Question 6

What will happen if we keep Silver chloride in sunlight also state it’s chemical reaction.

Answer 6

The white silver chloride changes turns into grey in sunlight due to the decomposition

The chemical equation is
2AgCl———2Ag + Cl2
Above the arrow is sunlight

Question 7

State a chemical reaction which can be used in Black and white photography and state what type of reaction it is.

Answer 7

The chemical reaction is
2AgBr——–2Ag + Br2
Above the arrow - sunlight

The type of reaction is decomposition