Import Question JSON
Current Question (ID: 7676)
Question:
$\text{1st }(\Delta H_1)\text{ and 2nd }(\Delta H_2)\text{ Ionization Enthalpies (in kJ mol}^{-1})\text{ and the }(\Delta_{eg}H)\text{ Electron Gain Enthalpy (in kJ mol}^{-1})\text{ of a few elements are given below:}$
$\begin{array}{|c|c|c|c|}
\hline
\text{Elements} & \Delta H_1 & \Delta H_2 & \Delta_{eg}H \\
\hline
\text{I} & 520 & 7300 & -60 \\
\text{II} & 419 & 3051 & -48 \\
\text{III} & 1681 & 3374 & -328 \\
\text{IV} & 1008 & 1846 & -295 \\
\text{V} & 2372 & 5251 & +48 \\
\text{VI} & 738 & 1451 & -40 \\
\hline
\end{array}$
$\text{The most reactive metal is:}$
Options:
-
1. $\text{VI}$
-
2. $\text{III}$
-
3. $\text{I}$
-
4. $\text{II}$
(Correct)
Solution:
$\text{HINT: Metals have low ionization enthalpy.}$
$\text{Explanation:}$
$\text{More reactive metal has a greater tendency to lose electrons and form positive ions. So, the metal with lowest ionization energy and highest electron gain enthalpy will be most reactive.}$
$\text{Element II is likely to be the most reactive metal as it has the lowest first ionization enthalpy }(\Delta H_1)\text{ and a low negative electron gain enthalpy }(\Delta_{eg}H)\text{.}$
$\text{Analysis of the data:}$
$\text{Looking at the first ionization enthalpies:}$
$\text{I: 520 kJ/mol}$
$\text{II: 419 kJ/mol (lowest)}$
$\text{III: 1681 kJ/mol}$
$\text{IV: 1008 kJ/mol}$
$\text{V: 2372 kJ/mol}$
$\text{VI: 738 kJ/mol}$
$\text{Element II has the lowest first ionization enthalpy (419 kJ/mol), making it the easiest to remove an electron from, which indicates high metallic reactivity.}$
$\text{The large jump from }\Delta H_1\text{ to }\Delta H_2\text{ for elements I and II (520 to 7300 and 419 to 3051 respectively) suggests these are alkali metals, with II being more reactive due to its lower first ionization energy.}$
Import JSON File
Upload a JSON file containing LaTeX/MathJax formatted question, options, and solution.