Chapter 9, Problem 3STP

Interpretation Introduction

Interpretation: The name of the compound ${\text{AlCl}}_{\text{3}}$ should be identified.

Concept Introduction: While naming an ionic compound, the elemental name of the metal is written followed by the name of the non-metal with the suffix ‘-ide’.

Answer to Problem 3STP

The name of the given compound ${\text{AlCl}}_{\text{3}}$ is aluminum trichloride. Hence option (A) is correct.

Explanation of Solution

The given compound ${\text{AlCl}}_{\text{3}}$ contains an aluminum atom and three chlorine atoms. Aluminum is metal while chlorine is non-metal. The prefix used for three is ‘tri’. The ionic compound is named as $\text{Metal}\text{name}+\text{Non-metal}\text{name}+ide$ .

Thus, the name of the compound is aluminum trichloride. Hence, option (A) is correct.

Conclusion

Aluminum exists only +3 oxidation state so (III) will not use for it. Aluminum chlorite and aluminum chloride are incorrect as chloride will be used and prefix ‘tri’ is missing/

Hence, options (B), (C), and (D) are incorrect.