NEET Practice Questions - Chemistry - The s-Block Elements

Which ion forms a hydroxide highly soluble in water?

(a) Ni²⁺

(b) K⁺

(c) Zn²⁺

(d) Al³⁺

What would you observe if excess of dilute NaOH solution is added and shaken with an aqueous solution of aluminium chloride?

(a) A permanent white precipitate is formed immediately

(b) No change at first but a white precipitate is formed on standing

(c) A white precipitate is formed which later dissolves

(d) A green precipitate which turns red on standing in air

A colourless salt gives violet colour to Bunsen flame and also turns moistured litmus paper blue. It Is:

(a) Na₂CO₃

(b) KNO₃

(c) K₂CO₃

(d) Cu(OH)₂

Strongest reducing agent among the following is:

(a) K

(b) Na

(c) Al

(d) Mg

When crystal of caustic soda is exposed to air, a liquid layer is deposited because:

(a) crystal melts

(b) crystal loses water

(c) crystal absorbs moisture and CO₂

(d) crystal sublimes

Which one of the following is formed on dissolving I₂ in aqueous solution of KI ?

(a) KIO₄

(b) KIO

(c) KI₃

(d) KIO₃

Which of the following statements is correct for CsBr₃?

(a) it is a covalent compound

(b) It contains Cs²⁺ and Br^- ions

(c) It contains Cs⁺, Br^- and Br₂ lattice molecules

(d) It contains Cs⁺ and ${\mathrm{Br}}_3^{-}$ ions

Hypo is chemically:

(a) Na₂S₂O₃.2H₂O

(b) Na₂S₂O₃.3H₂O

(c) Na₂S₂O₃.4H₂O

(d) Na₂S₂O₃.5H₂O

If NaOH is added to an aqueous solution of Zn²⁺ ions, a white precipitate appears and on adding axcess NaOH, the precepitate dissolves. In this solution zinc exists in the:

(a) cationic part

(b) anionic part

(c) both in cationic and anionic parts

(d) there is no zinc left in the solution

Brine is chemically:

(a) conc. solution of Na₂CO₃

(b) conc. solution of Na₂SO₄

(c) conc. solution of NaCl

(d) conc. solution of alum