Corrosion is a natural process, which converts a refined metal to a more chemically stable form, such as its oxide, hydroxide, or sulphide. It is the gradual destruction of materials (usually metals) by chemical or electrochemical reaction with their environment.Example rusting of iron is type of corrosion.

Complete the table given below Chemical reaction Substance Oxidised Substance reduced Oxidising agent Reducing agent 3 Fe + 4 H 2 O → Fe 3 O 4 + 4 H 2 H 2 S + Cl 2 → S + 2 HCl ZnO + C → Zn + CO MnO 2 + 4 HCl → MnCl 2 + 2 H 2 O + Cl 2 SO 2 + 2 H 2 S → 2 H 2 O + 3 S H 2 O + F 2 → HF + HOF 4 NH 3 + 5 O 2 → 4 NO + 6 H 2 O

Chemical reaction Substance Oxidised Substance reduced Oxidising agent Reducing agent 3 Fe + 4 H 2 O → Fe 3 O 4 + 4 H 2 Fe H 2 O H 2 O Fe H 2 S + Cl 2 → S + 2 HCl H 2 S Cl 2 Cl 2 H 2 S ZnO + C → Zn + CO C ZnO ZnO C MnO 2 + 4 HCl → MnCl 2 + 2 H 2 O + Cl 2 HCl MnO 2 MnO 2 HCl SO 2 + 2 H 2 S → 2 H 2 O + 3 S H 2 S SO 2 SO 2 H 2 S H 2 O + F 2 → HF + HOF H 2 O F 2 F 2 H 2 O 4 NH 3 + 5 O 2 → 4 NO + 6 H 2 O NH 3 O 2 O 2 NH 3 The chemical reactions in which oxidation and reduction reactions occur simultaneously are called redox reactions. An oxidising agent is a substance that causes oxidation by accepting electrons, therefore, it gets reduced. It can be also defined as a substance that provide oxygen or removes hydrogen during a chemical reaction. A reducing agent is a substance that causes reduction by losing electrons, therefore it gets oxidised.

E M B I B E

Science Chemistry>Chapter 1 - Chemical Reactions and Equations>Practice Questions>Q 2

MEDIUM

10th ICSE

IMPORTANT

Earn 100

State reasons for the following:
Potato chips manufacturers usually flush bags of chips with nitrogen gas.

Important Questions on Chemical Reactions and Equations

MEDIUM

10th ICSE

IMPORTANT

Science Chemistry>Chapter 1 - Chemical Reactions and Equations>Practice Questions>Q 2

State reasons for the following:
Iron articles loose their shine gradually.

MEDIUM

10th ICSE

IMPORTANT

Science Chemistry>Chapter 1 - Chemical Reactions and Equations>Practice Questions>Q 2

State reasons for the following:
Food should be kept in airtight containers.

MEDIUM

10th ICSE

IMPORTANT

Science Chemistry>Chapter 1 - Chemical Reactions and Equations>Practice Questions>Q 3

Define corrosion.

MEDIUM

10th ICSE

IMPORTANT

Science Chemistry>Chapter 1 - Chemical Reactions and Equations>Practice Questions>Q 4

What are the necessary conditions for rusting of iron?

MEDIUM

10th ICSE

IMPORTANT

Science Chemistry>Chapter 1 - Chemical Reactions and Equations>Practice Questions>Q 5

What do you mean by rancidity?

HARD

10th ICSE

IMPORTANT

Science Chemistry>Chapter 1 - Chemical Reactions and Equations>Practice Questions>Q 6

Complete the table given below

Chemical reaction	Substance Oxidised	Substance reduced	Oxidising agent	Reducing agent
$3 Fe + 4 H_{2} O \to {Fe}_{3} O_{4} + 4 H_{2}$
$H_{2} S + {Cl}_{2} \to S + 2 HCl$
$ZnO + C \to Zn + CO$
${MnO}_{2} + 4 HCl \to {MnCl}_{2} + 2 H_{2} O + {Cl}_{2}$
${SO}_{2} + 2 H_{2} S \to 2 H_{2} O + 3 S$
$H_{2} O + F_{2} \to HF + HOF$
$4 {NH}_{3} + 5 O_{2} \to 4 NO + 6 H_{2} O$

HARD

10th ICSE

IMPORTANT

Science Chemistry>Chapter 1 - Chemical Reactions and Equations>Practice Questions>Q 7

A brown substance 'X' on heating in the air forms a substance 'Y'. When hydrogen gas is passed over heated 'Y', it again changes into 'X'.
Name the substance 'X' and 'Y'.

HARD

10th ICSE

IMPORTANT

Science Chemistry>Chapter 1 - Chemical Reactions and Equations>Practice Questions>Q 7

A brown substance 'X' on heating in the air forms a substance 'Y'. When hydrogen gas is passed over heated 'Y', it again changes into 'X'.
Name the type of chemical reactions occurring during both the changes.