Question

Which of the reactions will need the maximum amount of energy? 4 points (a) Na → Na+ + e– (b) Ca+ → Ca++ + e– (c) K+ → K+ + + e– (d) C2+ → C3+ + e–

Answer 1

which of the reactions will need the maximum amount of energy ?

(a) Na ⇒Na⁺ + e¯

(b) Ca⁺ ⇒Ca⁺⁺ + e¯

(c) K⁺ ⇒K⁺⁺ + e¯

(d) C²⁺ ⇒C³⁺+ e¯

solution : This can be solved easily, if we write configuration of species.

configuration of Na = 1s², 2s², 2p⁶, 3s¹

here we see that one electron is present in 3s subshell, it is incomplete so it can be ejected easily. so energy required to eject is very low.

configuration of Ca⁺ = [Ar]4s¹ (incomplete 4s subshell)

so we can eject one more electron from its outermost shell. so energy required to remove it is also low but greater than option (a)

configuration of K⁺ = [Ar]4s⁰ [ inert gas configuration]

here K⁺ ion has inert gas configuration, it means it is stable and very high amount of energy required to remove another electron.

configuration of C²⁺ = 1s², 2s²

it is also a stable configuration. and energy required to remove another electron is high but energy for it is not as high as energy for K⁺.

so the maximum energy required to remove is for K⁺. Therefore option (c) is correct choice.

Answer 2

Answer:c

Explanation: