Question

The correct order for the wavelength of absorption in the
visible region is :
(a) [Ni(NO₂ )₆ ]⁴⁻ < [Ni(NH₃ )₆ ]²⁺
< [Ni(H₂O)₆]²⁺
(b) [Ni(NO₂ )₆ ]⁴⁻ < [Ni(H₂O)₆]²⁺
< [Ni(NH₃ )₆ ]²⁺
(c) [Ni(H₂O)₆]²⁺ < [Ni(NH₃ )₆ ]²⁺
< [Ni(NO₂ )₆ ]⁴⁻
(d) [Ni(NH₃ )₆ ]²⁺ < [Ni(H₂O)₆]²⁺
< [Ni(NO₂ )₆ ]⁴⁻

Answer 1

The correct order for the wavelength of absorption in the  visible region is

[Ni(H₂O)₆]²⁺ < [Ni(NH₃ )₆ ]²⁺ < [Ni(NO₂ )₆ ]⁴⁻.

Explanation:

• The three complexes of central metal ion is equal.
• The visible region of absorption depends on the ions.
• The crystal field stabilization energy orders the  values of ion raises in the series of spectrochemical.

              H2O < NH3 < $NO2} ^-$

• The number of "crystal field splitting" can be observed by

              Δ (H2O)< Δ (NH3)< Δ ($NO2}^-$)

• The same metal ion with different ion which shows absorption that depends upon the kinds of ion differently.
• The ion which is weak will make the central metal ion to absorb energy low which the wavelength is high.

To learn more;

1. https://brainly.in/question/7862764
2. https://brainly.in/question/11374503

Answer 2

(b) [Ni(NO₂ )₆ ]⁴⁻ < [Ni(H₂O)₆]²⁺

< [Ni(NH₃ )₆ ]²⁺

Let add both equation

5x + 3y = 9

+ 4x - 3y = (-18)

____________

9x = (-9)

:. x = (-1)

put this value in equation 1

\longrightarrow \rm 5x + 3y = 9⟶5x+3y=9

\longrightarrow \rm 5 \times ( - 1) + 3y = 9⟶5×(−1)+3y=9

\longrightarrow \rm ( - 5) + 3y = 9⟶(−5)+3y=9

\longrightarrow \rm 3y = 9 + 5⟶3y=9+5

\longrightarrow \rm 3y = 14⟶3y=14

\begin{gathered} \longrightarrow \blue{\boxed{ \rm y = \frac{14}{3} }}\\ \end{gathered}

⟶

y=

3

14