Selina solutions for Concise Chemistry [English] Class 10 ICSE chapter 2 - Chemical Bonding [1990 edition]

How do atoms attain noble gas configuration?

Define a chemical bond.

Define an electrovalent bond.

Define a covalent bond.

What are the conditions for the formation of an electrovalent bond?

An atom X has three electrons more than the noble gas configuration. What type of ion will it form?

An atom X has three electrons more than the noble gas configuration. Write the formula of its sulphate.

An atom X has three electrons more than the noble gas configuration. Write the formula of its nitrate.

An atom X has three electrons more than the noble gas configuration. Write the formula of its phosphate.

An atom X has three electrons more than the noble gas configuration. Write the formula of its carbonate.

An atom X has three electrons more than the noble gas configuration. Write the formula of its hydroxide.

Mention the basic tendency of an atom which makes it to combine with other atoms.

The element X has the electronic configuration 2, 8, 18, 8, 1. Without identifying x, predict the sign and charge on a simple ion of X.

The element X has the electronic configuration 2, 8, 18, 8, 1. Without identifying X, write if X will be an oxidising agent or a reducing agent and why.

In the formation of the compound XY₂, an atom X gives one electron to each Y atom. What is the nature of bond in XY₂? 

In the formation of the compound XY2, an atom X gives one electron to each Y atom. Draw the electron dot structure of this compound.

An atom X has 2, 8, 7 electrons in its shell. It combines with Y having 1 electron in its outermost shell.

What type of bond will be formed between X and Y?

An atom X has 2, 8, 7 electrons in its shell. It combines with Y, which has 1 electron in its outermost shell.

Write the formula of the compound formed.

Explain with the help of ionic equation and electron dot structural diagram the formation of the following electrovalent compound.

NaCl

Explain with the help of ionic equation and electron dot structural diagram the formation of the following electrovalent compound.

MgCl₂

Explain with the help of ionic equation and electron dot structural diagram the formation of the following electrovalent compound.

CaO

Compare:

Sodium atom and Sodium ion, with respect to

1. atomic structure
2. electrical state
3. chemical action
4. toxicity

Compare:

Chlorine atom and chloride ion, with respect to

1. atomic structure
2. electrical state
3. chemical action
4. toxicity

The electronic configuration of fluoride ion is the same as that of a neon atom. What is the difference between the two?

State the following is a reduction reaction or oxidation reaction.

\[\ce{Pb -> Pb^2+ + 2e-}\]

State the following is a reduction reaction or oxidation reaction.

\[\ce{Fe^2+ - e- -> Fe^3+}\]

State the following is a reduction reaction or oxidation reaction.

\[\ce{A^3+ + e- -> A^2+}\]

State the following is a reduction reaction or oxidation reaction.

\[\ce{Cu -> Cu^2+}\]

What do you understand by redox reactions?

Explain formation of electrovalent compound is a redox reaction.

Divide the following redox reaction into oxidation and reduction half-reaction.

\[\ce{Zn + Pb^2+ -> Zn^2+ + Pb}\]

Divide the following redox reaction into oxidation and reduction half-reaction.

\[\ce{Zn + Cu^2+ -> Zn^2+ + Cu}\]

Divide the following redox reaction into oxidation and reduction half-reaction.

\[\ce{Cl2 + 2Br- -> Br2 + 2Cl-}\]

Divide the following redox reaction into oxidation and reduction half-reaction.

\[\ce{Sn^2+ + 2Hg^2+ -> Sn^4+ + Hg2^2+}\]

Divide the following redox reaction into oxidation and reduction half-reaction.

\[\ce{2Cu+ -> Cu + Cu^2+}\]

Potassium (at No.19) and chlorine (at No.17) react to form a compound. Explain the formation of the compound on the basis of oxidation.

Potassium (at No.19) and chlorine (at No.17) react to form a compound. Explain the formation of the compound on the basis of reduction.

Potassium (at No.19) and chlorine (at No.17) react to form a compound. Explain the formation of the compound on the basis of oxidizing agent.

Potassium (at No.19) and chlorine (at No.17) react to form a compound. Explain the formation of the compound on the basis of reducing agent.

What are the conditions necessary for the formation of covalent molecules?

Elements A, B and C have atomic number 17, 19 and 10 respectively.

State which one is a non-metal.

Elements A, B and C have atomic number 17, 19 and 10 respectively.

State which one is a metal.

Elements A, B and C have atomic number 17, 19 and 10 respectively.

State which one is chemically inert.

Elements A, B and C have atomic number 17, 19 and 10 respectively.

Write down the formula of the compound formed by two of the above elements.

Draw the electron dot diagram and structure of nitrogen molecule.

Draw the electron dot diagram and structure of magnesium chloride.

Draw electron - dot structure and structural formula of methane.

What is the difference between ionic compounds and polar covalent compounds?

What is the difference between ionic compounds and covalent compounds?

What is the difference between a polar covalent compound and a non-polar covalent compound?

A solid is crystalline, has a high melting point and is water soluble. Describe the nature of the solid.

What do you understand by dipole (polar) molecule? 

Explain dipole (polar) molecule by taking hydrogen chloride as an example.

Explain the bonding in methane molecule using electron dot structure.

Methane molecule is non-polar molecule. Explain.

Give the characteristic properties of electrovalent compounds.

Give the characteristic properties of covalent compounds.

State the type of bond formed when the combining atom has zero E.N. difference. 

State the type of bond formed when the combining atom has small E.N. difference.

State the type of bond formed when the combining atom has a large E.N. difference.

State the type of bond formed, and draw Lewis structure of water.

State the type of bond formed, and draw Lewis structure of calcium oxide.

Explain the following:

Electrovalent compounds conduct electricity.

Explain the following:

Electrovalent compounds have a high melting point and boiling point while covalent compounds have low melting and boiling points.

Explain the following:

Electrovalent compounds dissolve in water whereas covalent compounds do not.

Explain the following:

Electrovalent compounds are usually hard crystals.

Explain the following: 

Polar covalent compounds conduct electricity?

Explain the following:

Water is a polar covalent molecule.

Elements X, Y, and Z have atomic numbers 6, 9 and 12 respectively. Which one forms an anion?

Elements X, Y, and Z have atomic numbers 6, 9 and 12 respectively. Which one forms a cation?

Elements X, Y, and Z have atomic numbers 6, 9 and 12 respectively. Which one :

State type of bond between Y and Z and give its molecular formula.

Taking MgCI₂ as an electrovalent compound, CCI₄ as a covalent compound, give four differences between electrovalent and covalent compounds.

Potassium chloride is an electrovalent compound, while hydrogen chloride is a covalent compound. But, both conducts electricity in their aqueous solutions. Explain.

Draw the electron dot structure of covalent compound methane (non polar) and HCL (polar) and give two difference between them.

Name two compounds that are covalent when taken pure but produce ions when dissolved in water.

An element M burns in oxygen to form an ionic bond MO. Write the formula of the compounds formed if this element is made to combine with chlorine and sulphur separately.

Element A has 2 electrons in its M shell. Element B has atomic number 7.

Write equations to show how A and B form ions.

Element A has 2 electrons in its M shell. Element B has atomic number 7.

If B is a diatomic gas, write the equation for the direct combination of A and B to form a compound.

Element A has 2 electrons in its M shell. Element B has atomic number 7.

If the compound formed between A and B is melted and an electric current is passed through the molten compound, the element A will be obtained at the ______ and B at the ______ of the electrolytic cell.

Element M forms a chloride with the formula MCI₂ which is a solid with high melting point. M would most likely be in the group in which ______ is placed.

Complete the following:

Compound X consists of molecules.

Choose the letter corresponding to the correct answer from the options A, B, C and D given below: 

The type of bonding in X will be ______.

Compound X consists of molecules.

Choose the letter corresponding to the correct answer from the options A, B, C and D given below:

X is likely to have a ______.

Compound X consists of molecules.

Choose the letter corresponding to the correct answer from the options A, B, C and D given below:

In the liquid state, X will ______.

For each compound mentioned above give the formulae of ions formed in aqueous solution.

Define a coordinate bond and give the conditions for its formation.

What do you understand by lone pair of electrons ?

State the type of bonding in the following molecule.

Water

State the type of Bonding in the following molecule:

Calcium oxide

State the type of bonding in the following molecule.
Hydroxyl ion

State the type of bonding in the following molecule.

Methane

State the type of bonding in the following molecule.

Ammonium ion

State the type of bonding in the following molecule.

Ammonium chloride

Draw an electron dot diagram for the formation of the following. State the type of bonding present in them.

Hydronium ion.

Draw an electron dot diagram for the formation of the following. State the type of bonding present in them.

Ammonium ion

Draw an electron dot diagram for the formation of the following. State the type of bonding present in them.

Hydroxyl ion

Give two example in the following case:

Co-ordinate bond compounds

Give two example in following case:

Solid covalent compounds

Give two example in following case:
Gaseous polar compounds

Give two example in following case:
Gaseous non polar compounds

Give two example in following case:
Liquid non polar compounds

Give an example in the following case:

Compound with electrovalent and covalent bond

Give an example in the following case:

Compound with all three types of bonds.

How many atoms of each kind are present in the following molecule:

Calcium oxide

How many atoms of each kind are present in the following molecule:

Chlorine

How many atoms of each kind are present in the following molecule:

water

How many atoms of each kind are present in the following molecule:

carbon tetrachloride

How many electrons are required or released by each atom in calcium oxide to attain the nearest noble gas configuration?

How many electrons are required or released by each atom in chlorine to attain the nearest noble gas configuration?

How many electrons are required or released by each atom in water molecule to attain the nearest noble gas configuration?

How many electrons are required or released by each atom in carbon tetrachloride to attain the nearest noble gas configuration?

Complete the following:

When the nuclei of two different reacting atoms are of ______ mass, then a bond so formed is called ______ covalent bond. (equal, unequal, polar, non-polar)

Complete the following:

In case of non-polar covalent bond, the covalent bond is formed in the ______ of atoms and shared electrons are ______ distributed. (corner, middle, equally, unequally)

Complete the following:

Ionic or electrovalent compounds do not conduct electricity in their ______ state.

Complete the following:

The ions in ______ compounds are held very strongly due to strong ______ forces. (electrovalent, covalent, electromagnetic, electrostatic).

Electrons are getting added to an element Y: 

Is Y getting oxidised or reduced?

Electrons are getting added to an element Y: 

which electrode will Y migrate to during the process of electrolysis?

Acids dissolve in water and produce positively charged ions. Draw the structure of these positive ions.

Explain why Carbon tetrachloride does not dissolve in water.

Elements Q and S react together to form an ionic compound. Under normal conditions, which physical state will the compound QS exist in?

Can Q and S both be metals? Justify your answer.

The property which is characteristic of an electrovalent compound is that ______.

When a metal atom becomes an ion ______.

In the formation of magnesium chloride (by direct combination between magnesium and chlorine) name the substance that is oxidized and the substance that is reduced.

What is the term defined below?

A bond formed by a shared pair of electrons, each bonding atom contributing one electron to the pair.

What is the term defined below?

A bond formed by a shared pair of electrons with both electrons coming from the same atom.