Chemical bonds

Which of these statements is/are correct?

• Valence electrons are electrons occupying the innermost shell.

• Covalent bond is form due to sharing of a pair of electron by two atoms.

• The strength of a covalent bond depends on number of shared electrons

• The bond between the two oxygen atoms in a molecule of oxygen is single covalent bond.

Which of these statements is/are correct?

• Electronegativity is the atom’s affinity for electrons.

• The more electronegative an atom is, the less strongly it attracts shared electrons toward itself

• The bond between C and H atom in methane is non polar covalent bond.

• The bond between H atom and N atom in ammonia polar covalent bond

(a)   is formed by the attraction of oppositely charged ions.

Which of these statements is/are correct?

• In a water molecule, the hydrogen atom has partially positive charge while the oxygen atom has a partially negative charge.

• In an ammonium molecule, the hydrogen has partially positive charge while the N atom has a partially negative charge.

• The hydrogen atom of a water molecule is linked by Van der Walls interaction to nitrogen atom of ammonium

• Hydrogen bond is a strong bond while Van der Walls interaction is a weak bond.

• Van der Waals interaction between molecule exists due to impermanent local partial charges.

(a)   are compounds with the same molecular formula but different structures and properties

Why pentane and 2-methyl butane are called structural isomers.

Which of these statements is/are correct?

• Geometric isomers have the same covalent arrangements but differ in spatial arrangements of the atom

• The two Xs in cis isomer are on opposite side.

• The two Xs in trans isomer are on the same side.

• Enantiomer exists due to differences in the spatial arrangement around an asymmetric carbon.

Which of these statements is/are correct.

• Functional group is the part of the molecule that involves in chemical reaction.

• Hydroxyl group is polar due to the presence of a strongly electronegative oxygen atom.

• An aldehyde has a carbonyl group positioned at the end of the carbon skeleton while a ketone has an internal carbonyl group

• Carboxyl group has base properties because the covalent bond between oxygen and hydrogen is polar.

Write the correct structural formula for each of the functional group.