Impurity Insights Defects in Strontium chloride

The video tutorial explains defects in ionic crystals, focusing on metal cation defects, metal deficiency defects, and impurity defects. It describes how unipositive metal cations create vacancies, leading to electrical imbalance, and how dipositive ions replace them to maintain neutrality. Transition metals with variable valences exhibit metal deficiency defects, as seen in ferrous oxide. Impurity defects occur when foreign ions replace parent ions, affecting electrical conductivity. The tutorial uses examples like sodium chloride and strontium ions to illustrate these concepts.

What happens when a unipositive metal cation leaves its lattice site in an ionic crystal?

• It creates a cation vacancy or hole.

• It increases the crystal's temperature.

• It forms a new crystal structure.

• It decreases the crystal's mass.

Which of the following is an example of a metal deficiency defect?

• Sodium chloride

• Ferrous oxide

• Magnesium sulfate

• Calcium carbonate

What is added to sodium chloride to demonstrate impurity defects?

• Calcium chloride

• Strontium chloride

• Potassium chloride

• Magnesium chloride

In the context of impurity defects, what replaces two sodium ions in the crystal lattice?

• Two magnesium ions

• One strontium ion

• Two potassium ions

• One calcium ion

How does the presence of a cation vacancy affect the crystal?

• It increases the mobility of ions and electrical conductivity.

• It decreases the crystal's density.

• It increases the crystal's color intensity.

• It decreases the crystal's melting point.