NEETChemistryCoordination Compounds
Given below are two statements: Statement I: The molar conductivity of [ Co(NH ₃)₆] Cl ₃ in aqueous solution is greater than that of [ Co(NH ₃)₄ Cl ₂] Cl . Statement II: The primary valency of cobalt is different in these two complexes, which causes the difference in their molar conductivities. In the light of the above statements, choose the most appropriate answer from the options given below:
Options
- AStatement I is correct but Statement II is incorrect
- BBoth Statement I and Statement II are correct
- CBoth Statement I and Statement II are incorrect
- DStatement I is incorrect but Statement II is correct
Correct answer
A. Statement I is correct but Statement II is incorrect
Step-by-step solution
Statement I is correct because [ Co(NH ₃)₆] Cl ₃ ionises to give 4 ions ( [ Co(NH ₃)₆]³⁺ and 3 Cl ⁻ ), whereas [ Co(NH ₃)₄ Cl ₂] Cl ionises to give only 2 ions ( [ Co(NH ₃)₄ Cl ₂]⁺ and Cl ⁻ ). A greater number of ions in solution results in higher molar conductivity. Statement II is incorrect because the primary valency corresponds to the oxidation state of the central metal atom. In both complexes, cobalt is in the +3 oxidation state. The difference in molar conductivity is due to the number of ionisable counter i