Tag: defining lattice energy

Questions Related to defining lattice energy

The correct order of the lattice energies of the following ionic compound is :

chemistry lattice energy defining lattice energy ionic or electrovalent bond energy cycles

  1. $NaCl > MgBr _2 > CaO > Al _2O3$

  2. $NaCl > CaO > MgBr _2 > Al _2O _3
    $

  3. $Al _2O _3 > MgBr _2 > CaO > NaCl$

  4. $Al _2O _3 > CaO > MgBr _2 > NaCl$

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Correct Option: D
Explanation:

Charge matter in lattice energy so here $Al^{+3}, Ca^{+2}, Mg^{+2}, Na^+$ and $O^{-2}$ & $Br^{-1}$
So $cao>MgBr _2 \Rightarrow$ overall order $Al _2O _3>Cao>MgBr _2>NaCl.$

$MgO$ has a high melting point because due to the highly charged ions, ionic force is strong and lattice energy is........

chemistry lattice energy defining lattice energy ionic or electrovalent bond energy cycles

  1. High

  2. Low

  3. Both are

  4. None of these

Show answer
Correct Option: A
Explanation:

lattice energy is high

In magnesium oxide, both magnesium and oxygen atoms form ions in the lattice. Due to the higher magnitude of the charge on the magnesium and oxygen atoms, the force of attraction between them is very high. This provides them with very high lattice energy and a lot of energy is required to break this lattice. Hence the melting point of $MgO$ is high. Therefore both the statements are correct and statement 2 is the correct explanation for statement 1