in each rack, pick the compound with the bigger lattice energy.
note: lattice energy is always greater than zero.
which compound has the bigger lattice energy?
NaCl or Na2S
KCl or KBr
Li2O or BeO
The Correct Answer and Explanation is :
1. NaCl vs Na2S:
Answer: Na2S
Explanation:
Lattice energy is directly influenced by the charges of the ions involved and the ionic radii. The higher the charges on the ions, the greater the lattice energy, because stronger electrostatic forces result in a more stable lattice structure.
- NaCl consists of Na⁺ and Cl⁻ ions, whereas Na2S consists of Na⁺ and S²⁻ ions.
- The charge on the sulfur ion (S²⁻) is -2, which is higher than the charge on the chloride ion (Cl⁻) which is -1.
- The greater the charge on the ions, the stronger the electrostatic attraction, leading to a greater lattice energy. Therefore, Na2S has a higher lattice energy than NaCl.
2. KCl vs KBr:
Answer: KCl
Explanation:
Here, we are comparing potassium chloride (KCl) and potassium bromide (KBr). Both compounds contain potassium ions (K⁺), but the anions are different.
- The chloride ion (Cl⁻) is smaller than the bromide ion (Br⁻).
- Lattice energy increases with the smaller ion because the ions can get closer together, enhancing the electrostatic attraction.
- Since Cl⁻ is smaller than Br⁻, KCl has a greater lattice energy than KBr.
3. Li2O vs BeO:
Answer: BeO
Explanation:
This is a comparison between lithium oxide (Li2O) and beryllium oxide (BeO), both of which contain highly charged oxide ions (O²⁻).
- Li₂O has Li⁺ ions, while BeO has Be²⁺ ions. The charge on the Be²⁺ ion is higher than that of the Li⁺ ion, which leads to stronger electrostatic attraction between the ions in BeO.
- Additionally, the small size of the Be²⁺ ion compared to Li⁺ allows the ions to pack more tightly, increasing the lattice energy.
- As a result, BeO has a higher lattice energy than Li₂O.
Summary:
- Na2S > NaCl
- KCl > KBr
- BeO > Li2O
Let me generate the image to visually explain these concepts.
Here is the diagram illustrating the comparison of lattice energies between NaCl vs Na2S, KCl vs KBr, and Li2O vs BeO. It shows the ions involved, their charges, and the relationship between charge size and lattice energy. The arrows indicate the increasing lattice energy based on charge and ion size.
Let me know if you need any further clarification!
