Question

Which of the following is true about the melting temperature of potassium chloride? The melting temperature is relatively high. The melting temperature is variable and unpredictable. The melting temperature is relatively low. Potassium chloride does not melt.

Answer 1

Answer:f

• First option: the melting temperature is relatively high.

Explanation:

You can look at the melting temperature at any table that summarizes the main properties of this compound, potassium chloride.

Such melting point is 770 °C, which is relatively high.

Why is this?

Potassium chloride is a ionic compound formed by the cations of potassium, K⁺, and the chloride anions, Cl⁻. Its unit formula is KCl.

The ionic bond between K and Cl is possible because each K atom is able to yield its valence electron to one Cl atom which has 7 valence electrons.

Then, the K atoms become positive ions (cations) K⁺, while Cl atoms become negative ions (Cl⁻).

These two ions with opposite charge are bonded by the force of electrostatic attraction. This is a ionic bond.

Melting point, so as boiling point along with other physical properties, depends on the attraction force between the atoms.

Hence, since the attrative forces between the ions are relatively strong, the melting point of the ionic compounds, such as potassium chloride, are relatively high.