Complete and balance the following equations: H 2 O 2 → MnO 2 _____ + O 2

Hydrogen peroxide decomposes in the presence of a catalyst manganese dioxide in the water and liberates oxygen. It is a laboratory preparation of oxygen. The balanced reaction is as follows: 2 H 2 O 2 → MnO 2 2 H 2 O + O 2

Complete and balance the following equation: HgO → heat _____ + O 2

When mercuric oxide is heated it decomposes into mercury and liberates oxygen gas. The balanced equation is as follows: 2 HgO → heat 2 Hg + O 2

Complete and balance the following equation: KNO 3 → heat _____ + O 2

When potassium nitrate is strongly heated it decomposes into potassium nitrite and liberates oxygen. The balanced equation is as follows: 2 KNO 3 → heat 2 KNO 2 + O 2

Complete and balance the following equation: Fe + O 2 → moisture _____

Iron in the presence of oxygen and moisture forms a reddish brown layer of iron oxide over the surface of the iron. This is called rust. The balanced equation for the reaction is as follows: 4 Fe + 3 O 2 → moisture ( xH 2 O ) 2 Fe 2 O 3 . xH 2 O

E M B I B E

Innovative Chemistry>Chapter 8 - Air and Atmosphere>EVALUATE YOUR UNDERSTANDING>Q III

MEDIUM

7th ICSE

IMPORTANT

Earn 100

Why oxygen is necessary for combustion?

Important Questions on Air and Atmosphere

MEDIUM

7th ICSE

IMPORTANT

Innovative Chemistry>Chapter 8 - Air and Atmosphere>EVALUATE YOUR UNDERSTANDING>Q III

Why is oxygen collected by the downward displacement of water?

HARD

7th ICSE

IMPORTANT

Innovative Chemistry>Chapter 8 - Air and Atmosphere>EVALUATE YOUR UNDERSTANDING>Q III

What is acid rain? Why is it harmful?

MEDIUM

7th ICSE

IMPORTANT

Innovative Chemistry>Chapter 8 - Air and Atmosphere>EVALUATE YOUR UNDERSTANDING>Q III

Which gas is used for flushing food packages? Why?

MEDIUM

7th ICSE

IMPORTANT

Innovative Chemistry>Chapter 8 - Air and Atmosphere>EVALUATE YOUR UNDERSTANDING>Q III

Carbon dioxide plays no role in respiration but all life would come to an end if there were no carbon dioxide in the air. Support this statement with relevant facts.

MEDIUM

7th ICSE

IMPORTANT

Innovative Chemistry>Chapter 8 - Air and Atmosphere>EVALUATE YOUR UNDERSTANDING>Q III

Complete and balance the following equations:

$H_{2} O_{2} \overset{{MnO}_{2}}{\to}_____+ O_{2}$