Question

Consider the following changes $M(s) \longrightarrow M(g)$ $M(g) \longrightarrow M^{2+}(g)+2 e^{-}\ldots$(1) $M(g) \longrightarrow M^{+}(g)+e^{-}\ldots$(2) $M^{+}(g) \longrightarrow M^{2+}(g)+e^{-} \ldots$ (3) $M(g) \longrightarrow M^{2+}(g)+2 e^{-}\ldots$(4) The second ionisation energy of $M$ could be determined from the energy values associated with

• A. 1 + 2 + 4
• B. 1 + 5 - 3
• C. 2 + 3 - 4
• D. 44684

Answer 1

The Correct Option is D

The second ionisation energy is the energy that is required to remove the second electron from a positive charge ion. The second ionization energy  is greater than the first ionization energy. For example: Li → Li+ + e- and second ionization energy is Li+ → Li2+ + e-

According to the question 5-1 should be done to get the second ionisation energy. 

M (g) → M2+ +2e- - M (g) → M+ +e- 

Second ionisation energy is the amount of energy required to take out an electron from the monopositive cation. 
\({ M(g) -> M^{2+} (g) + 2e^- }\) .......(5) 
\({ M (g) -> M^{+} (g) + e^- }\) ....(3) 
On subtracting eq(iii) form e (v) we get, 
\({ M^{+} (g) -> M^{2+} (g) + e^- }\)