Exams › JEE Main › Chemistry

Two complexes [Cr(H2O)6]Cl3 (A) and [Cr(NH3)6]Cl3 (B) are violet and yellow coloured, respectively. The incorrect statement regarding them is: (1) Δo value for (A) is less than that of (B). (2) both absorb energies of corresponding their complementary colors. (3) Δo values of (A) and (B) are calculated from the energies of violet and yellow light, respectively. (4) both are paramagnetic with three unpaired electrons.

1. Δo value for (A) is less than that of (B).
2. both absorb energies of corresponding their complementary colors.
3. Δo values of (A) and (B) are calculated from the energies of violet and yellow light, respectively.
4. both are paramagnetic with three unpaired electrons.

Correct answer: both absorb energies of corresponding their complementary colors.

Solution

The correct option states that both complexes absorb energies of their complementary colors, which is true because the color observed is the result of the wavelengths of light that are not absorbed. Therefore, the complexes will absorb light corresponding to the colors opposite to those they exhibit.

Related JEE Main Chemistry questions

• When sodium hydroxide is introduced into an aqueous Zn2+ solution, a white precipitate forms, and this precipitate dissolves when more NaOH is added. In such a solution, zinc is present in the:
• When excess ammonia is added to a copper sulphate solution, a deep blue colour appears because of the formation of which species?
• In the nitroprusside ion, iron and NO are present as Fe$^{2+}$ and NO$^+$ instead of Fe$^{3+}$ and NO. These two formulations can be distinguished by
• In the brown ring test for nitrite and nitrate ions, the characteristic brown ring is produced because a complex ion is formed with which formula?
• What is the spin-only magnetic moment, expressed in Bohr magnetons (μB), for Ni²⁺ in aqueous solution? (Atomic number of Ni = 28)
• Silver chloride dissolves in aqueous ammonium hydroxide because it leads to the formation of which species?

⚔️ Practice JEE Main Chemistry free + battle 1v1 →