Question

2 mark for review the ionic compounds nacl and mgs are represented by the diagrams above. which statement correctly identifies diagram 1 and identifies the compound with the lower melting point, explaining why?

Explanation:

Step1: Analyze ion - charges

Ionic compounds with higher - charged ions have stronger ionic bonds. In $NaCl$, $Na^+$ has a + 1 charge and $Cl^-$ has a - 1 charge. In $MgS$, $Mg^{2 + }$ has a + 2 charge and $S^{2 - }$ has a - 2 charge. Stronger ionic bonds lead to higher melting points.

Step2: Identify diagrams

The size of ions also matters in ionic lattice structure. Generally, larger ions result in a less - tightly packed lattice. Since $Na^+$ and $Cl^-$ are relatively larger ions compared to $Mg^{2+}$ and $S^{2 - }$ in terms of ionic radii, and $NaCl$ has lower - charged ions. Diagram 1 represents $NaCl$ because of the larger ion sizes and lower - charged ions. $NaCl$ has a lower melting point than $MgS$ due to weaker ionic bonds (resulting from lower ion charges).

Answer:

Diagram 1 represents $NaCl$, and $NaCl$ has the lower melting point because it has ions with lower charges ($Na^+$ and $Cl^-$ with + 1 and - 1 charges respectively) compared to $MgS$ ($Mg^{2+}$ and $S^{2 - }$ with + 2 and - 2 charges respectively), resulting in weaker ionic bonds.