Selina solutions for Concise Chemistry [English] Class 10 ICSE chapter 3 - Acids, Bases and Salts [1990 edition]

What do you understand by the term, acid?

Name the positive ion formed When an acid is dissolved in water.

Draw the structure of Hydronium ion.

Write the ionization of sulphuric acid showing the formation of hydronium ion.

Water is never added to acid in order to dilute it why?

Define the term ‘basicity’ of an acid.

Give the basicity of nitric acid.

Give the basicity of sulphuric acid.

Give the basicity of phosphoric acid.

Give two examples of the following:

oxy-acid

Give two examples of the following:

hydracids

Give two examples of the following:

tribasic acid

Give two examples of the following:

dibasic acid

Name the acidic anhydride of the following acid:

Sulphurous acid

Name the acidic anhydride of the following acid:

Nitric acid

Name the acidic anhydride of the following acid:

Phosphoric acid

Name the acidic anhydride of the following acid:

Carbonic acid

Name the acid present in vinegar.

Name the acid present in grapes.

Name the acid present in lemon.

What do you understand by the statement ‘acetic acid is a monobasic acid'?

Give a balanced equation for reaction of nitrogen dioxide with water.

Give a balanced equation for preparation of a non-volatile acid from a volatile acid.

What do you understand by the strength of an acid?

On which factor does the strength of an acid depend?

Explain the following:

Carbonic acid gives an acid salt but hydrochloric acid does not. 

Explian the following:

Dil. HCl acid is stronger than highly concentrated acetic acid. 

Explain the following:

H₃PO₃ is not a tribasic acid.

Explain the following:

Lead carbonate does not react with dilute HCl.

Explain the following:

Nitrogen dioxide is a double acid anhydride.

How is an acid prepared from a non-metal? Give an equation for it.

How is an acid prepared from a salt? Give an equation for it.

Give an equation to show how the following is made from their corresponding anhydride.

sulphurous acid

Give an equation to show how the following is made from their corresponding anhydride.

phosphoric acid

Give an equation to show how the following is made from their corresponding anhydride.

carbonic acid

Give an equation to show how the following is made from their corresponding anhydride.

sulphuric acid

Name an acid used to flavor and preserve food.

Name an acid used in a drink.

Name an acid used to remove ink spots.

Name an acid used as an eyewash.

Give the reaction of acid with chlorides. State the conditions under which they react.

Give the reaction of acid with nitrates. State the conditions under which they react.

Write the balanced equation for the preparation of the following compound (as major product) starting from iron and using only one other substance:

Iron (II) chloride

Write the balanced equation for the preparation of the following compound (as the major product) starting from iron and other substance:

Iron (III) chloride

Write the balanced equation for the preparation of the following compound (as major product) starting from iron and using only one other substance:

Iron (II) sulphate

Write the balanced equation for the preparation of the following compound (as major product) starting from iron and using only one other substance:

Iron (II) sulphide

Write a balanced reaction for the following conversions (A, B, C, D)

\[\ce{Fe→[A]FeCl2 →[B]FeCO3→[C]Fe(NO3)2→[D]Fe(OH)2}\]

The preparation of Lead sulphate from Lead carbonate is a two-step process. (Lead sulphate cannot be prepared by adding dilute Sulphuric acid to Lead carbonate.)

What is the first step that is required to prepare Lead sulphate from Lead carbonate?

The preparation of lead sulphate from lead carbonate is a two step process (lead sulphate cannot be prepared by adding dilute sulphuric acid to lead carbonate.)

Write the equation for the reaction that will take place when this first step is carried out.

The preparation of lead sulphate from lead carbonate is a two step process (lead sulphate cannot be prepared by adding dilute sulphuric acid to lead carbonate)

Why is the direct addition of dilute sulphuric acid to lead carbonate an impractical method of preparing lead sulphate?

What is the term defined by the following?

A salt containing a metal ion surrounded by other ions or molecules.

What is the term defined by the following?

A base which is soluble in water.

Making use only of substances chosen from those given below:

(Dilute sulphuric acid, sodium carbonate, Zinc, sodium sulphite, Lead, calcium carbonate)

Give the equation for the reaction by which you could obtain hydrogen.

Making use only of substances chosen from those given below:

(Dilute sulphuric acid, sodium carbonate, Zinc, sodium sulphite, Lead, calcium carbonate)

Give the equation for the reaction by which you could obtain sulphur dioxide.

Making use only of substances chosen from those given below:

(Dilute sulphuric acid, sodium carbonate, Zinc, sodium sulphite, Lead, calcium carbonate)

Give the equation for the reaction by which you could obtain carbon dioxide.

Making use only of substances chosen from those given below:

(Dilute sulphuric acid, sodium carbonate, Zinc, sodium sulphite, Lead, calcium carbonate)

Give the equation for the reaction by which you could obtain zinc carbonate (two steps required).

What do you understand by an alkali?

Give two examples of strong alkalis.

Give two examples of weak alkalis.

What is the difference between an alkali and a base?

What is the difference between the chemical nature of an aqueous solution of HCl and an aqueous solution of NH₃

Name the ions furnished by bases in solution.

Name the ions furnished by an acid.

Give one example in the following case:

A basic oxide which is soluble in water.

Give one example in the following case:

A hydroxide which is highly soluble in water.

Give one example in the following case:

A basic oxide which is insoluble in water.

Give one example in the following case:

A hydroxide which is insoluble in water.

Give one example in the following case:

A weak mineral acid.

Give one example in the following case:

A base which is not an alkali.

Give one example in the following case:

An oxide which is a base.

Give one example in the following case:

A hydrogen containing compound which is not an acid.

Give one example in the following case:

A base which does not contain a metal ion.

You have been provided with three test tubes. One of them contains distilled water and the other two have an acidic solution and a basic solution respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?

HCl, HNO₃, C₂H₅OH, C₆H₁₂O₆ all contain H atoms but only HCI and HNO₃ show acidic character. Why?

Dry HCI gas does not change the colour of dry litmus paper. Why?

Is PbO₂ a base or not? Comment.

Do basic solutions also have H⁺_(aq)? Why are they basic?

How would you obtain a base from another base.

How would you obtain an alkali from a base.

How would you obtain salt from another salt?

Write balanced equation to satisfy the following statement:

\[\ce{Acid + Active metal -> Salt + hydrogen}\]

Write balanced equation to satisfy the following statement:

\[\ce{Acid + Base -> Salt + water}\]

Write balanced equation to satisfy the following statement:

\[\ce{Acid + Carbonate or bicarbonate -> Salt + water + Carbon dioxide}\]

Write balanced equation to satisfy the following statement:

\[\ce{Acid + Sulphite or bisulphite -> Salt + water + sulphur dioxide}\]

Write balanced equation to satisfy the following statement:

\[\ce{Acid + sulphide -> Salt + Hydrogen sulphide}\]

The skin has and needs natural oils. Why is it advisable to wear gloves while working with strong allkalis?

Complete the table:

What do you understand by pH value?

Two solutions X and Y have Ph values of 4 and 10 respectively. Which one of these two will give a pink colour with phenolphthalein indicator?

You are supplied with five solutions: A, B, C, D and E with pH values as follows: A = 1.8, B = 7, C = 8.5, D = 13, and E = 5

Classify these solutions as neutral, slightly or strongly acidic and slightly or strongly alkaline.

Which solution would be most likely to liberate hydrogen with magnesium powder. Give a word equation for each reaction.

You are supplied with five solutions: A, B, C, D and E with pH values as follows: A = 1.8, B = 7, C = 8.5, D = 13, and E = 5

Classify these solutions as neutral, slightly or strongly acidic and slightly or strongly alkaline.

Which solution would be most likely to liberate hydrogen with powdered zinc metal. Give a word equation for each reaction.

Distinguish between a common acid base indicator and a universal indicator.

Distinguish between acidity of bases and basicity of acids.

Distinguish between acid and alkali (other than indicators).

What should be added to Increase the pH value .

What should be added to Decrease the pH value of a neutral solution? 

How does tooth enamel get damaged? What should be done to prevent it?

When you use universal indicator, you see that solutions of different acids produce different colours. Indeed, solution of the same acid with different concentrations will also give different colours. Why?

A solution has a pH of 7. Explain how you would increase its pH .

A solution has a pH of 7. Explain how you would decrease its pH.

If a solution changes the colour of litmus from red to blue, what can you say about its pH?

What can you say about the pH of a solution that liberates carbon dioxide from sodium carbonate?

Solution P has a pH of 13, solution Q has a pH of 6 and solution R has a pH of 2.

Which solution will liberate ammonia from ammonium sulphate on heating?

Solution P has a pH of 13, solution Q has a pH of 6 and solution R has a pH of 2.

Which solution is a strong acid?

Solution P has a pH of 13, solution Q has a pH of 6 and solution R has a pH of 2.

Which solution contains molecules as well as ions?

M is an element in the form of a powder. M burns in oxygen and the product obtained is soluble in water. The solution is tested with litmus. Write down only the word which will correctly complete the following sentence.

If M is a metal, then the litmus will turn ______.

M is an element in the form of a powder. M burns in oxygen and the product obtained is soluble in water. The solution is tested with litmus. Write down only the word which will correctly complete the following sentence.

If M is a non-metal, then the litmus will turn ______.

M is an element in the form of a powder. M burns in oxygen and the product obtained is soluble in water. The solution is tested with litmus. Write down only the word which will correctly complete the following sentence.

If M is a reactive metal, then ______ will be evolved when M reacts with dilute sulphuric acid.

M is an element in the form of a powder. M burns in oxygen and the product obtained is soluble in water. The solution is tested with litmus. Write down only the word which will correctly complete the following sentence.

If M is a metal, it will form ______ oxide, which will form ______ solution with water.

M is an element in the form of a powder. M burns in oxygen and the product obtained is soluble in water. The solution is tested with litmus. Write down only the word which will correctly complete the following sentence.

If M is a non-metal, it will not conduct electricity in the form of ______.

Define the following and give two examples in case a normal salt .

Define the following and give two examples in case an acid salt .

Define the following and give two examples in case a basic salt.

What is a ‘salt’?

Answer the following question related to salts and their preparations:

What kind of salt is prepared by precipitation?

Name a salt prepared by direct combination. Write an equation for the reaction that takes place in preparing the salt you have named.

Name the procedure used to prepare a sodium salt such as sodium sulphate.

Explain the following method with example. 

Direct combination

Explain the following method with example. 

Displacement

Explain the following method with example.  

Double decomposition (precipitation)

Explain the following method with example.  

Neutralisation of insoluble base

Explain the following method with example. 

Neutralisation of an alkali (titration)

How would you prepare :

Copper sulphate crystals from a mixture of charcoal and black copper oxide.

How would you prepare:

zinc sulphate crystals from zinc dust (powdered zinc and zinc oxide).

How would you prepare:

sodium hydrogen carbonate crystals.

How would you prepare:

Calcium sulphate from calcium carbonate

The following is a list of methods for the preparation of salts.

A – direct combination of two elements

B – reaction of a dilute acid with a metal.

C – reaction of a dilute acid with an insoluble base.

D – titration of a dilute acid with a solution of soluble base.

E – reaction of two solutions of salts to form a precipitate.

Choose from the above list A to E, the best method of preparing the following salt by giving a suitable equation in the following case:

Anhydrous ferric chloride.

The following is a list of methods for the preparation of salts.

A – direct combination of two elements

B – reaction of a dilute acid with a metal.

C – reaction of a dilute acid with an insoluble base.

D – titration of a dilute acid with a solution of soluble base.

E – reaction of two solutions of salts to form a precipitate.

Choose from the above list A to E, the best method of preparing the following salt by giving a suitable equation in the following case:

Lead chloride.

The following is a list of methods for the preparation of salts.

A – direct combination of two elements.

B – reaction of a dilute acid with a metal.

C – reaction of a dilute acid with an insoluble base.

D – titration of a dilute acid with a solution of soluble base.

E – reaction of two solutions of salts to form a precipitate.

Choose from the above list A to E, the best method of preparing the following salt by giving a suitable equation in the following case:

Sodium sulphate.

The following is a list of methods for the preparation of salts.

A – direct combination of two elements.

B – reaction of a dilute acid with a metal.

C – reaction of a dilute acid with an insoluble base.

D – titration of a dilute acid with a solution of soluble base.

E – reaction of two solutions of salts to form a precipitate.

Choose from the above list A to E, the best method of preparing the following salt by giving a suitable equation in the following case:

Copper sulphate.

Name a chloride which is insoluble in cold water but dissolves in hot water.

Name a chloride which is insoluble.

Name two sulphates which are insoluble.

Name a basic salt.

Name an acidic salt.

Name a mixed salt.

Name a complex salt.

Name a double salt.

Fill in the blanks with suitable words:

An acid is a compound which when dissolved in water forms hydronium ions as the only ______ ions. A base is a compound which is soluble in water and contains ______ ions. A base reacts with an acid to form a ______ and water only. This type of reaction is known as ______.

What would you observe when blue litmus is introduced into a solution of hydrogen chloride gas?

What would you observe when red litmus paper is introduced into a solution of ammonia in water?

What would you observe when red litmus paper is introduced in Caustic soda solution?

Explain why It is necessary to find out the ration of reactants required in the preparation of sodium sulphate.

Explain why fused calcium chloride is used in the preparation of FeCI₃?

Explain why Anhydrous FeCl₃ cannot be prepared by heating hydrated iron (III) chloride.

Give the preparation of the salt shown in the left column by matching with the methods given in the right column. Write a balanced equation for each preparation.

Give the pH value of pure water.

Does pH value of pure water change if common salt is added to it?

Classify the following solutions as acids, bases or salts.

Ammonium hydroxide, barium chloride, sodium chloride, sodium hydroxide, H₂SO₄ and HNO₃

Complete the following table and write one equation for each to justify the statement: 

Write the balanced equation for the preparation of the following salt in the laboratory:

A soluble sulphate by the action of an acid on an insoluble base.

Write the balanced equation for the preparation of the following salt in the laboratory:

An insoluble salt by the action of an acid on another salt.

Write the balanced equation for the preparation of the following salt in the laboratory:

An insoluble base by the action of a soluble base on a soluble salt.

Write the balanced equation for the preparation of the following salt in the laboratory:

A soluble sulphate by the action of an acid on a metal.

You are provided with the following chemicals:

NaOH, Na₂CO₃, H₂O, Zn(OH)₂, CO₂, HCI, Fe, H₂SO₄, CI₂, Zn.

Using the suitable chemicals from the given list only, state briefly how you would prepare iron (III) chloride.

You are provided with the following chemicals:

NaOH, Na₂CO₃, H₂O, Zn(OH)₂, CO₂, HCI, Fe, H₂SO₄, CI₂, Zn.

Using the suitable chemicals from the given list only, state briefly how you would prepare sodium sulphate.

You are provided with the following chemicals:

NaOH, Na₂CO₃, H₂O, Zn(OH)₂, CO₂, HCI, Fe, H₂SO₄, CI₂, Zn.

Using the suitable chemicals from the given list only, state briefly how you would prepare sodium zincate.

You are provided with the following chemicals:

NaOH, Na₂CO₃, H₂O, Zn(OH)₂, CO₂, HCI, Fe, H₂SO₄, CI₂, Zn.

Using the suitable chemicals from the given list only, state briefly how you would prepare iron (II) sulphate.

You are provided with the following chemicals:

NaOH, Na₂CO₃, H₂O, Zn(OH)₂, CO₂, HCI, Fe, H₂SO₄, CI₂, Zn.

Using the suitable chemicals from the given list only, state briefly how you would prepare sodium chloride.

For each of the salt: A, B, C and D, suggest a suitable method of its preparation.

A is a sodium salt.

For each of the salt: A, B, C and D, suggest a suitable method of its preparation.

B is an insoluble salt.

For each of the salt: A, B, C and D, suggest a suitable method of its preparation.

C is a soluble salt of copper.

For each of the salt: A, B, C and D, suggest a suitable method of its preparation.

D is a soluble salt of zinc.

Choosing only substances from the list given in the box below, write equations for the reactions which you would use in the laboratory to obtain: Sodium sulphate

Choosing only substances from the list given in the box below, write equations for the reactions which you would use in the laboratory to obtain: Copper sulphate.

Choosing only substances from the list given in the box below, write equations for the reactions which you would use in the laboratory to obtain: lron(II) sulphate

Choosing only substances from the list given in the box below, write equations for the reactions which you would use in the laboratory to obtain: Zinc carbonate.

From the formula listed below, choose one, in the following case, corresponding to the salt having the given description: 

AgCl, CuCO₃, CuSO₄.5H₂O, KNO₃, NaCl, NaHSO₄, Pb(NO₃)₂, ZnCO₃, ZnSO₄.7H₂O.

An acid salt.

From the formula listed below, choose one, in the following case, corresponding to the salt having the given description: 

AgCl, CuCO₃, CuSO₄.5H₂O, KNO₃, NaCl, NaHSO₄, Pb(NO₃)₂, ZnCO₃, ZnSO₄.7H₂O.

An insoluble chloride.

From the formula listed below, choose one, in the following case, corresponding to the salt having the given description: 

AgCl, CuCO₃, CuSO₄.5H₂O, KNO₃, NaCl, NaHSO₄, Pb(NO₃)₂, ZnCO₃, ZnSO₄.7H₂O.

On treating with concentrated sulphuric acid, this salt changes from blue to white.

From the formula listed below, choose one, in the following case, corresponding to the salt having the given description: 

AgCl, CuCO₃, CuSO₄.5H₂O, KNO₃, NaCl, NaHSO₄, Pb(NO₃)₂, ZnCO₃, ZnSO₄.7H₂O.

On heating, this salt changes from green to black.

From the formula listed below, choose one, in the following case, corresponding to the salt having the given description: 

AgCl, CuCO₃, CuSO₄.5H₂O, KNO₃, NaCl, NaHSO₄, Pb(NO₃)₂, ZnCO₃, ZnSO₄.7H₂O.

This salt gives nitrogen dioxide on heating.

Ca(H₂PO₄)₂ is an example of a compound called _______ .

Write the balanced equation for the reaction of:

A named acid and a named alkali.

State the term defined by the following sentence:

A soluble base.

State the term defined by the following sentence:

The insoluble solid formed when two solutions are mixed together.

State the term defined by the following sentence:

An acidic solution in which there is only partial ionisation of the solute molecules.

Which of the following methods, (a), (b), (c), (d) or (e) is generally used for preparing the chlorides listed below from (i) to (v). Answer by writing down the chloride and the letter pertaining to the corresponding method. Each letter is to be used only once.
(a) Action of an acid on a metal.
(b) Action of an acid on an oxide or carbonate.
(c) Direct combination.
(d) Neutralization of an alkali by an acid.
(e) Precipitation (double decomposition).
(i) copper(II) chloride.
(ii) iron(II) chloride.
(iii) iron(IIl) chloride.
(iv) lead (II) chloride.
(v) sodium chloride.

Choose the most appropriate answer from

(SO₂, SiO₂, Al₂O₃, CO, MgO, Na₂O)

A covalent oxide of a metalloid.

Choose the most appropriate answer from

(SO₂, SiO₂, Al₂O₃, CO, MgO, Na₂O)

An oxide which when dissolved in water form acid.

Choose the most appropriate answer from

(SO₂, SiO₂, Al₂O₃, CO, MgO, Na₂O)

A basic oxide.

Choose the most appropriate answer from

(SO₂, SiO₂, Al₂O₃, CO, MgO, Na₂O)

An amphoteric oxide.

What do you understand by water of crystallization?

Give four substances which contain water of crystallization and write their common names.

Define efflorescence.

Give examples of efflorescence.

Define deliquescence.

Give examples of deliquescence.

Answer the question below:

What name is given to the water in the compound copper sulphate-5-water?

Answer the question below:

If copper sulphate-5-water is heated, anhydrous copper sulphate is formed. What is its colour?

Answer the question below:

By what means, other than heating, could you dehydrate copper sulphate-5-water and obtain anhydrous copper sulphate?

Answer the question below:

Name a deliquescent salt.

Answer the question below:

Why hydrated copper sulphate turns white on heating.

State your observation when the following is exposed to the atmosphere.

Washing soda crystals

State your observation when the following is exposed to the atmosphere.

Iron (III) chloride salts

Give reason for the following:

Sodium hydrogen sulphate is not an acid but it dissolves in water to give hydrogen ions, according to the equation

\[\ce{NaHSO4 <=> H+ + Na+ + SO^2-_4}\]

Give reason for the following:

Anhydrous calcium chloride is used in a desiccator.

Explain clearly how conc, H₂SO₄ is used as dehydrating as well as drying agent.

Distinguish between drying and dehydrating agent.

State whether a sample of the following would increase or decrease in a mass if exposed to air.

Solid NaOH.

State whether a sample of the following would increase or decrease in a mass if exposed to air.

Solid CaCI₂

State whether a sample of the following would increase or decrease in a mass if exposed to air.

Solid Na₂CO₃ .10H₂O

State whether a sample of the following would increase or decrease in a mass if exposed to air.

Conc. Sulphuric acid

State whether a sample of the following would increase or decrease in a mass if exposed to air.

Iron (III) Chloride

Why does common salt get wet during the rainy season?

How can this impurity be removed?

Name a substance which changes the blue colour of copper sulphate crystals to white.

Name two crystalline substances which do not contain water of crystallization.

Name the salt which on hydrolysis forms acidic. Give a balanced equation for the following reaction.

Name the salt which on hydrolysis forms neutral solution. Give a balanced equation for each reaction.

State the change noticed when blue litmus and red litmus is introduced in the following solution:

Na₂CO₃ solution

State the change noticed when blue litmus and red litmus is introduced in the following solution:

NaCl solution

State the change noticed when blue litmus and red litmus is introduced in the following solution:

NH₄NO₃

State the change noticed when blue litmus and red litmus is introduced in the following solution:

MgCl₂ Solution