Covalent Bonding

Q.

An element A has four electrons in the outermost shell of its atom and combines with another element B having seven electrons in the outermost shell. The compound formed does not conduct electricity. Give any two properties of this compound.

Q. Covalent compounds are generally ___ in water.

Q. Which of the following is incorrect for covalent compounds?

1. Low melting points
2. Low boiling points
3. Mostly insoluble in water
4. Good conductors of electricity

Q.

Choose the correct option based on the statements given below:

Statement 1: Carbon always shares electrons or forms a covalent bond with other elements.

Statement 2: $C^{4+}$ and $C^{4-}$ ions are highly unstable.

1. Both statements are correct but statement 2 is not the correct explanation for statement 1

2. Both statements are correct and statement 2 is the correct explanation for statement 1

3. Statement 1 is incorrect

4. Statement 2 is incorrect

Q. In covalent compounds, the constituent atoms share the electrons with each other.

1. True
2. False

Q.

When the similar atoms combine, they form a molecule of a/an ___.

Q.

Compare hydrogen and halogen on the basis of -

(i) Physical state

(ii) Ion formation

(iii) Valency

(iv) Reaction with oxygen

Q.

Molecules are made of a combination of similar atoms only.

1. True
2. False

Q.

Write the molecular formula, electron dot formula, and structural formula for ethane.

Q.

A covalent hydride?

Q. A single covalent bond is formed by sharing of two electrons between two atoms.

1. True
2. False

Q. The total number of shared electrons in the lewis dot structure of a $O_2$ molecule is .

1. four
2. two
3. six
4. three

Q. Statement 1: Carbon always shares electrons or forms a covalent bond with other elements.

Statement 2: $C^{4+}$ and $C^{4-}$ ions are highly unstable.

1. Statement 1 and statement 2 are correct, but statement 2 is not the reason for statement 1.
2. Statement 1 and 2 are correct and statement 2 is the reason for statement 1.
3. Statement 1 is incorrect.
4. Statement 2 is incorrect.

Q.

Define or explain the term :

Covalent or molecular compound

Q. Covalent compounds are generally:

1. bad conductors of electricity
2. semiconductors of electricity
3. good conductors of electricity
4. none of these

Q. The property which is characteristic of an electrovalent compound is that :

1. it is easily vaporised
2. it has a high melting point
3. it often exists as a liquid
4. it is a weak electrolyte

Q. In the below image, the number of electron pairs that do not participate in bonding is/are ______.

1. four
2. eight
3. one
4. two

Q.

Which amongst the following molecules consist of a triple bond?

1. Hydrogen chloride ($HCl$)
2. Oxygen molecule ($O_2$)
3. Nitrogen molecule ($N_2$)
4. Fluorine molecule ($F_2$)

Q. A hydrogen molecule contains two hydrogen atoms in it.

1. False
2. True

Q. In a $H_2$ molecule, one pair of electrons is shared between the two hydrogen atoms.

1. False
2. True

Q. The number of electron pairs involved in the formation of a triple bond are ________.

1. three
2. six
3. two
4. four

Q.

The list of some substances is given below.

HCl, H₂O, Cl₂, NaBr, CH₄, NH₃, N₂, O₂, CaO, HF, I₂, and Br₂,

From the list above choose the substance/substances:

Which is non-polar covalent liquid.

Q. Which of the following charectors favors the strong covalent bond :

1. Bigger atomic size of the atom
2. Smaller atomic size of the atoms
3. Low ionization energy
4. Less nuclear force of attraction on outer electrons