A mixture containing Cu²⁺ and Ni²⁺ can be separated for identification by

• passing H₂S in acid medium

• passing H₂S in alkaline medium

• passing H₂S in neutral medium

• passing H₂S in dry mixture

Chlorine cannot displace

• fluorine from NaF

• iodine from NaI

• bromine from NaBr

• None of the above

The electronic configuration of an element is 1s²,2s² 2p⁶, 3s² 3p⁶, 3d¹⁰, 4s² 4p³. To which of the following elements it is similar in properties?

• Boron

• Oxygen

• Nitrogen

• Chlorine

Which of the following will replace Br₂ from the aqueous solution having bromide ion?

• Cl₂

• I${}_3^{⊝}$

• I₂

• Cl^{${}^{⊝}$}

In which of the following compound the oxidation number of oxygen is +2?

• H₂O₂

• CO₂

• H₂O

• OF₂

Which of the following is pseudo halogen?

• IF₇

• (CN)₂

• ICl${}_2^{-}$

• I${}_3^{-}$

977.

Correct order of electron affinities of halogens is

• F> Cl> Br> I

• I> Br> Cl> F

• Cl> F>I>Br

• Cl>F>Br>I

If NO₂(N₂O₄) is dissolved in NaOH, we get solution of

• NaNO₂

• NaNO₃

• mixture of NaNO₂ and NaNO₃

• NaNO₄

Hypochlorous acid is

• HOCl

• HClO₂

• HClO₃

• HClO₄

Which one of the following gases has both oxidising as well as reducing property?

• CO

• SO₂

• H₂S

• PH₃