Which of the following ionic compounds has the highest melting point?
Help: Lattice energy
Select one:
a. Cs2O
b. K2O
c. BeO
d. SrO
e. LiF
f. CsI
Which of the following ionic lattices would have the highest melting point?
A. Potassium oxide
B. Beryllium oxide
C. Boron nitride
D. Lithium chloride
To determine which ionic compound has the highest melting point, we need to consider the concept of lattice energy. Lattice energy is the energy released when ions come together to form a solid lattice structure. It is influenced by the charges and sizes of the ions.
In general, larger charges and smaller ion sizes result in stronger attractive forces and higher lattice energies, leading to higher melting points.
Looking at the options provided:
a. Cs2O: Cs has a charge of +1, and O has a charge of -2.
b. K2O: K has a charge of +1, and O has a charge of -2.
c. BeO: Be has a charge of +2, and O has a charge of -2.
d. SrO: Sr has a charge of +2, and O has a charge of -2.
e. LiF: Li has a charge of +1, and F has a charge of -1.
f. CsI: Cs has a charge of +1, and I has a charge of -1.
To compare the melting points, we need to evaluate the charges and the sizes of the ions. Generally, higher charges and smaller ion sizes contribute to higher melting points.
Among the options given, the ion with the highest charge is +2, found in BeO and SrO. Comparing their respective ions, Be is smaller in size than Sr.
In general, smaller ions with higher charges result in stronger attractions, leading to higher melting points. Based on this information, BeO (c) is likely to have the highest melting point among the given options.
To determine which of the following ionic compounds has the highest melting point, you need to consider the concept of lattice energy.
Lattice energy is the energy released when a crystal lattice is formed from its constituent ions. It is influenced by factors such as the charge on the ions and the distance between them. Generally, the higher the lattice energy, the stronger the ionic bond, and the higher the melting point of the compound.
In this case, we need to compare the lattice energies of the given compounds.
Let's analyze each compound:
a. Cs2O: Cesium oxide has a +1 charge on the cesium ion (Cs+) and a -2 charge on the oxide ion (O2-). Since the charges are larger than those of the other compounds, we can expect a stronger ionic bond.
b. K2O: Potassium oxide has a +1 charge on the potassium ion (K+) and a -2 charge on the oxide ion (O2-). The charges are the same as those in Cs2O, so we can expect a similar strength of the ionic bond.
c. BeO: Beryllium oxide has a +2 charge on the beryllium ion (Be2+) and a -2 charge on the oxide ion (O2-). Since the charges are smaller than those of the other compounds, we can expect a weaker ionic bond.
d. SrO: Strontium oxide has a +2 charge on the strontium ion (Sr2+) and a -2 charge on the oxide ion (O2-). The charges are the same as those in BeO, so we can expect a similar strength of the ionic bond.
e. LiF: Lithium fluoride has a +1 charge on the lithium ion (Li+) and a -1 charge on the fluoride ion (F-). The charges are smaller than those of the other compounds, so we can expect a weaker ionic bond.
f. CsI: Cesium iodide has a +1 charge on the cesium ion (Cs+) and a -1 charge on the iodide ion (I-). The charges are larger than those of the other compounds, so we can expect a stronger ionic bond.
Based on the analysis of the charges, we can determine that the compounds with the highest melting points are those with larger charges on the ions, indicating a stronger ionic bond. The compound with the highest melting point among the given options is CsI (cesium iodide).
Therefore, the correct answer is f. CsI.