# Viraf J. Dalal solutions for Class 7 New Simplified Middle School Chemistry chapter 5 - Language of Chemistry [Latest edition]

## Chapter 5: Language of Chemistry

Chemical EquationsExerciseObjective Type Questions
Chemical Equations

### Viraf J. Dalal solutions for Class 7 New Simplified Middle School Chemistry Chapter 5 Language of Chemistry Chemical Equations

Chemical Equations | Q 1

Write word equation for the following molecular equation:

CuCo3 → CuO + CO2 [g]

Word equation:

State the characteristics or indications occurring in the above reaction.

Chemical Equations | Q 2

Write word equation for the following molecular equation:

$\ce{CaCO3 + 2HCl ->[\triangle] CaCl2 + H2O + CO2 [g]}$

Word equation:

State which characteristic does [g] in the above reaction indicate. The word equation of:

Chemical Equations | Q 3

Write word equation for the following molecular equation:

$\ce{NH3 [g] + HCl [g] ⇌ NH4Cl [s]}$

Word equation:
State which characteristic is observed in the above reaction.

Give an-example of a similar above characteristic, seen between two other gaseous reactants.

Chemical Equations | Q 4

Write word equation for the following molecular equation:

Na2SO3 + 2HCl [dil.] → 2NaCl + H2O + SO2 [g]

Chemical Equations | Q 5

Write word equation for the following molecular equation:

FeSO4 + 2NaOH →Na2SO4 + Fe(OH)2 ↓

Word equation:

State why [↓] indication is seen after Fe(OH)2 and not after Na2SO4

Chemical Equations | Q 6

Write word equation for the following molecular equation:

$\ce{N2 + 3H2 ⇌[Fe - 450°C][200 atoms] 2NH3 + \triangle}$

Word equation:
State why [+ Δ] indication is seen after NH3.
State what 200 atmospheres – indicates.
State the function of Fe in the above reaction.

Chemical Equations | Q 7

Write word equation for the following molecular equation:

$\ce{H2 [g] + Cl2 [g] ->[sunlight] 2HCl}$

Word equation:

State which form of energy is utilised in the above chemical reaction.

Chemical Equations | Q 8

Write word equation for the following molecular equation:

AgN03 + HCI → HNO3 + AgCl ↓

Word equation:

State whether AgCl is soluble or insoluble in HN03.

Chemical Equations | Q 9

Write word equation for the following molecular equation:

CaO + H20 → Ca (OH)2 + Δ

Word equation:

State why [+ Δ ] is not written in the reaction, if ZnO reacts with H2O.

Chemical Equations | Q 10

Write word equation for the following molecular equation:

CuS04 + 2NaOH→Na2S04 + Cu(OH)2↓

Word equation:

State the colour of the products.

Exercise

### Viraf J. Dalal solutions for Class 7 New Simplified Middle School Chemistry Chapter 5 Language of Chemistry Exercise

Exercise | Q 1

Explain the term ‘chemical reaction’ with special reference to – ‘reactants’ and ‘products’.

Exercise | Q 2

Represent the addition of dilute sulphuric acid to zinc by means of a chemical equation. State the function of the arrow between the reactants and products.

Exercise | Q 3.1

A chemical reaction is generally accompanied by certain external indications or characteristics. These include – change of – (a) colour (b) state (c) smell (d) evolution of gas (e) formation of precipitate (f) evolution or absorption of heat. With reference to change of colour – state the change in colour seen when the following are heated – copper carbonate.

Exercise | Q 3.2

A chemical reaction is generally accompanied by certain external indications or characteristics. These include – change of – (a) colour (b) state (c) smell (d) evolution of gas (e) formation of precipitate (f) evolution or absorption of heat. With reference to change of colour – state the change in colour seen when the following are heated – zinc carbonate.

Exercise | Q 3.3

A chemical reaction is generally accompanied by certain external indications or characteristics. These include – change of – (a) colour (b) state (c) smell (d) evolution of gas (e) formation of precipitate (f) evolution or absorption of heat. With reference to change of colour – state the change in colour seen when the following are heated – mercury [II] oxide.

Exercise | Q 3.4

A chemical reaction is generally accompanied by certain external indications or characteristics. These include – change of – (a) colour (b) state (c) smell (d) evolution of gas (e) formation of precipitate (f) evolution or absorption of heat. With reference to change of colour – state the change in colour seen when the following are heated –  lead [IV] oxide.

Exercise | Q 4

Give a balanced equation for addition of iron to copper [II] sulphate solution. State the change in colour seen.

Exercise | Q 5.1

In certain reaction a change of state is observed i.e. solid to liquid, liquid to gas etc. – State the change of state of the products – to give the respective reactant.

C + 2S → CS2

Exercise | Q 5.2

In certain reaction a change of state is observed i.e. solid to liquid, liquid to gas etc. – State the change of state of the products – to give the respective reactant.

NH3 + HCl ⇌ NH4Cl

Exercise | Q 5.3

In certain reaction a change of state is observed i.e. solid to liquid, liquid to gas etc. – State the change of state of the products – to give the respective reactant.

2H2 + O2 → 2H2O

Exercise | Q 5.4

In certain reaction a change of state is observed i.e. solid to liquid, liquid to gas etc. – State the change of state of the products – to give the respective reactant.

$\ce{2H2O ->[electric][current] 2H2 + O2}$

Exercise | Q 6

In certain reactions a change of smell is observed. Give two examples from daily life of the same.

Exercise | Q 7.1

In certain reaction an insoluble solid called precipitate is formed. State the colour and name of the precipitate formed in the following reaction involving addition of:

Dilute hydrochloric acid to silver nitrate.

Exercise | Q 7.2

In certain reaction an insoluble solid called precipitate is formed. State the colour and name of the precipitate formed in the following reaction involving addition of:

Iron [II] sulphate to sodium hydroxide.

Exercise | Q 7.3

In certain reaction an insoluble solid called precipitate is formed. State the colour and name of the precipitate formed in the following reaction involving addition of:

Iron [III] chloride to ammonium hydroxide.

Exercise | Q 7.4

In certain reaction an insoluble solid called precipitate is formed. State the colour and name of the precipitate formed in the following reaction involving addition of:

Copper [II] sulphate to sodium hydroxide.

Exercise | Q 7.5

In certain reaction an insoluble solid called precipitate is formed. State the colour and name of the precipitate formed in the following reaction involving addition of:

Exercise | Q 8

Give examples of exothermic reactions i.e. heat evolved in each of the following:

(a) reaction between a solid and a liquid
(b) reaction between two gases
Give two examples of exothermic reactions seen in everyday life.

Exercise | Q 9.1

Give one example in the case where supplying energy [given below] is necessary for a chemical reaction.

Heat energy

Exercise | Q 9.2

Give one example in the case where supplying energy [given below] is necessary for a chemical reaction.

Light energy

Exercise | Q 9.3

Give one example in the case where supplying energy [given below] is necessary for a chemical reaction.

Electrical energy

Exercise | Q 9.4

Give one example in the case where supplying energy [given below] is necessary for a chemical reaction.

Pressure

Exercise | Q 9.5

Give one example in the case where supplying energy [given below] is necessary for a chemical reaction.

Catalyst

Exercise | Q 10.1

Representation of the results of a chemical change – is a chemical equation.

For the equation: FeCl3 + 3NH4OH 3NH4Cl + Fe(OH)3 ↓

Write the word equation for the above molecular equation.

Exercise | Q 10.2

Representation of the results of a chemical change – is a chemical equation.

For the equation: FeCl3 + 3NH4OH 3NH4Cl + Fe(OH)3 ↓

Is the equation given above a balanced equation. Give reasons.

Exercise | Q 10.3

Representation of the results of a chemical change – is a chemical equation.

For the equation: FeCl3 + 3NH4OH 3NH4Cl + Fe(OH)3 ↓

Name the reactants and the products in the above equation.

Exercise | Q 10.4

Representation of the results of a chemical change – is a chemical equation.

For the equation: FeCl3 + 3NH4OH 3NH4Cl + Fe(OH)3 ↓

What is the indications of the arrow between the reactants and the products and of the arrow pointing downwards at the end.

Exercise | Q 11.1

Give word equation for the following chemical reaction and give the names of the product formed.

Zn + 2HC1→ ZnCl2 + H2

Exercise | Q 11.2

Give word equation for the following chemical reaction and give the names of the product formed.

CuO + H2SO4→CuS04 + H2O

Exercise | Q 11.3

Give word equation for the following chemical reaction and give the names of the product formed.

Zn + S → ZnS

Exercise | Q 11.4

Give word equation for the following chemical reaction and give the names of the product formed.

ZnCO3 → ZnO + CO2

Exercise | Q 11.5

Give word equation for the following chemical reaction and give the names of the product formed.

NH3 + HCl→ NH4Cl

Objective Type Questions

### Viraf J. Dalal solutions for Class 7 New Simplified Middle School Chemistry Chapter 5 Language of Chemistry Objective Type Questions

Objective Type Questions | Q 1.1

Select the correct answer for the following options:

The black residue obtained on heating copper carbonate.

• Hydrogen

• Copper [II] oxide

• Oxygen

• Copper [II] hydroxide

• Ammonia

Objective Type Questions | Q 1.2

Select the correct answer for the following options:

The basic gas obtained when two gases react in presence of a catalyst and the reaction is exothermic.

• Hydrogen

• Copper [II] oxide

• Oxygen

• Copper [II] hydroxide

• Ammonia

Objective Type Questions | Q 1.3

Select the correct answer for the following options:

The gas obtained when potassium chlorate is heated in the presence of a catalyst.

• Hydrogen

• Copper [II] oxide

• Oxygen

• Copper [II] hydroxide

• Ammonia

Objective Type Questions | Q 1.4

Select the correct answer for the following options:

The pale blue precipitated obtained when copper [II] sulphate reacts with sodium hydroxide.

• Hydrogen

• Copper [II] oxide

• Oxygen

• Copper [II] hydroxide

• Ammonia

Objective Type Questions | Q 1.5

Select the correct answer for the following options:

The gas which reacts with oxygen to give a neutral liquid.

• Hydrogen

• Copper [II] oxide

• Oxygen

• Copper [II] hydroxide

• Ammonia

Objective Type Questions | Q 2.1

Give a word equation for the following reaction.

Two solids which combine on heating, to give a liquid.

Objective Type Questions | Q 2.2

Give a word equation for the following reaction.

Two gases which combine to give a solid.

Objective Type Questions | Q 2.3

Give a word equation for the following reaction.

A compound which on heating shows – colour change from brown to yellow.

Objective Type Questions | Q 2.4

Give a word equation for the following reaction.

A salt which reacts with ammonium hydroxide to give a reddish brown precipitate.

Objective Type Questions | Q 2.5

Give a word equation for the following reaction.

An exothermic reaction where both the reactants are gases, one of which is oxygen.

Objective Type Questions | Q 3.1

Name the following:

The silvery residue obtained on heating mercury [II] oxide.

Objective Type Questions | Q 3.2

Name the following:

The gas evolved when a dilute acid is added to chalk [limestone].

Objective Type Questions | Q 3.3

Name the following:

Two non-metal which react explosively when brought in close contact.

Objective Type Questions | Q 3.4

Name the following:

Two gases which react under pressure in presence of a catalyst at elevated temperatures to give a gaseous product.

Objective Type Questions | Q 3.5

Name the following:

A catalyst which increases the rate of a chemical reaction.

Objective Type Questions | Q 4.1

Give reason for the following:

Even though rusting is an exothermic reaction, the heat evolved when an iron nail rusts is unnoticeable.

Objective Type Questions | Q 4.2

Give reason for the following:

Electrolytic decomposition of water is a reaction involving change of state.

Objective Type Questions | Q 4.3

Give reason for the following:

A characteristic change of colour is seen when a piece of iron is added to copper [II] sulphate solution.

Objective Type Questions | Q 4.4

Give reason for the following:

The catalytic oxidation of sulphur dioxide to sulphur trioxide is represented by a double arrow {⇌}
between the reactants and products, formed in the chemical reaction.

Objective Type Questions | Q 4.5

Give reason for the following:

Silver salts are kept in dark coloured bottles.

Objective Type Questions | Q 5.1

Write word equation for the following chemical reaction given below. Also state the observation seen in the case.

$\ce{ZnCo3->[\triangle] ZnO + CO2}$

Objective Type Questions | Q 5.2

Write word equation for the following chemical reaction given below. Also state the observation seen in the case.

NaCl + AgNo3 → AgCU ↓ + NaN03

Objective Type Questions | Q 5.3

Write word equation for the following chemical reaction given below. Also state the observation seen in the case.

$\ce{Na2SO3 + 2HCl ->[\triangle] 2NaCl + H2O + SO2}$

Objective Type Questions | Q 5.4

Write word equation for the following chemical reaction given below. Also state the observation seen in the case.

$\ce{2SO2 + O2 ⇌[V2O5][450°C] 2SO3}$

Objective Type Questions | Q 5.5

Write word equation for the following chemical reaction given below. Also state the observation seen in the case.

Pb(NO3)2 + 2NH4OH → 2NH4N03 + Pb(OH)2↓

## Chapter 5: Language of Chemistry

Chemical EquationsExerciseObjective Type Questions

## Viraf J. Dalal solutions for Class 7 New Simplified Middle School Chemistry chapter 5 - Language of Chemistry

Viraf J. Dalal solutions for Class 7 New Simplified Middle School Chemistry chapter 5 (Language of Chemistry) include all questions with solution and detail explanation. This will clear students doubts about any question and improve application skills while preparing for board exams. The detailed, step-by-step solutions will help you understand the concepts better and clear your confusions, if any. Shaalaa.com has the CISCE Class 7 New Simplified Middle School Chemistry solutions in a manner that help students grasp basic concepts better and faster.

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Concepts covered in Class 7 New Simplified Middle School Chemistry chapter 5 Language of Chemistry are Classification of Change: Chemical Changes, Chemical Equation, Chemical Reaction, Conditions Necessary for Chemical Reactions, Indicators of a Chemical Change (Chemical Reaction), Balancing Chemical Equation.

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