The first and second ionisation enthalpies of a metal are 496 and 4560 kJ mol–1, respectively. How many moles of HCl and H2SO4, respectively, will be needed to react completely with 1 mole of the metal hydroxide ?
Solution
First ionization enthalpies = 496 kJ/mole
<br><br>Second ionization enthalpies = 4560 kJ/mol
<br><br>According to the given information, the difference between first and second ionization enthalpy is very high so Metal belong to 1st group i.e. Monovalent cation.
<br><br>Metal hydroxide will be of type, MOH.
<br><br>MOH + HCl $\to$ MCl + H<sub>2</sub>O
<br><br>MOH + ${1 \over 2}$H<sub>2</sub>SO<sub>4</sub>
$\to$
${1 \over 2}$M<sub>2</sub>SO<sub>4</sub> + H<sub>2</sub>O
<br><br>So one mole of HCl required to react with one
mole MOH.
<br><br>And ${1 \over 2}$ mole of H<sub>2</sub>SO<sub>4</sub> required to react with one
mole MOH.
About this question
Subject: Chemistry · Chapter: Periodic Table and Periodicity · Topic: Periodic Trends
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