Do you expect the carbon hydrides of the type (Cn H2n+2 ) to act as ‘Lewis’ base or acid? Justify.

For carbon hydrides which belong to type (C_n H_2n+2), the following hydrides are possible for

n = 1⇒CH₄

n = 2⇒C₂ H₆

n = 3⇒C₃ H₈

For a hydride to act as a Lewis acid, it should be electron deficient.

Lewis acid = electron accepting

Also, for a hydride to act as a Lewis base, it should be electron rich.

Lewis base = electron donating

Taking C₂ H₆ as an example, the total number of electrons are 14  and the total covalent bonds are 7. Hence, the bonds are regular 2e^– 2centered bonds.

Hence, hydride C₂ H₆ has sufficient electrons to be represented by a conventional Lewis structure. Therefore, it is an electron-precise hydride, having all atoms with octets. Thus, it can neither accept nor donate electrons to act as a Lewis base or Lewis acid.