At 300 K and 1 atmospheric pressure, 10 mL of a hydrocarbon required 55 mL of O₂ for complete combustion, and 40 mL of CO₂ is formed. The formula of the hydrocarbon is :

Three complexes,
[CoCl(NH₃)₅] ²⁺(I),
[Co(NH₃)₅H₂O]³⁺ (II) and
[Co(NH₃)₆] ³⁺(III)
absorb light in the visible region. The correct order of the wavelength of light absorbed by them is :

Consider the following statements
(a) The pH of a mixture containing 400 mL of 0.1 M H₂SO₄ and 400 mL of 0.1 M NaOH will be approximately 1.3
(b) Ionic product of water is temperature dependent.
(c) A monobasic acid with Ka = 10^–5 has pH = 5. The degree of dissociation of this acid is 50 %.
(d) The Le Chatelier's principle is not applicable to common-ion effect.

The correct statements are :

Increasing rate of S_N1 reaction in the following compounds is :