NEET Questions Solved


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 Br3- ions

(d) CsBr3          Cs++ Br3-

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NO2 is obtained by heating:

(a) CsNO3

(b) KNO3

(c) LiNO3

(d) NaNO3

(c) 2LiNO3         Li2O + 2NO2 + 12O2

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Excess of dilute sodium hydroxide solution is gradually added with shaking to an aqueous solution of zinc sulphate. What would you observe?

(a) A light blue precipitate is first formed which finally dissolves to give a deep blue solution

(b) A white precipitate appears which dissolves to give a colourless solution.

(c) A white precipitation is formed which does not dissolve 

(d) No change takes place and the solution remains clear

(b) ZnSO4 + 2NaOH         Zn(OH)2 + Na2SO4                                              ppt.

Zn(OH)2 + 2NaOH         Na2ZnO2 + 2H2O                                               soluble

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Which has lowest thermal stability?

(a) Li2CO3

(b) Na2CO3

(c) K2CO3

(d) Rb2CO3

(a) Li2CO3 decomposes on heating;

                 Li2CO3           Li2O + CO2

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Which alkali metal reacts with nitrogen to form nitride?

(a) Li

(b) Na

(c) Cs

(d) None of the above

(a) Only Li combines directly with nitrogen to form lithium nitride,

                   6Li + N2          2Li3N

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The most basic oxide among the following is:

(a) Na2O

(b) BaO

(c) As2O3

(d) Al2O3

(a) The basic character of oxides decreases along the period.

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The most dangerous method of precipitating hydrogen would be by the action of HCl on:

(a) Zn

(b) Fe

(c) K

(d) Al

(c) K reacts with HCl violently.

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 Na2COand NaHCO3 may be distinguished by treating their aqueous solution with:

(a) litmus solution

(b) dil. acid

(c) MgO

(d) MgSO4

(d) Na2CO3 reacts with MgSO4 to give basic magnesium carbonate.

   2MgSO4 + 2Na2CO3 + H2O       MgCO3.Mg(OH)2 + 2Na2SO4 + CO2

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Which is industrially prepared by the electrolysis of aqueous NaCl?

(a) Na2CO3

(b) NaHCO3

(c) NaOH 

(d) NaOCl

(c) Cathode: 2H2O + 2e         H2 + 2OH-Anode:                  2Cl-        Cl2 + 2e

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Sodium cannot be extracted by the electrolysis of brine solution because:

(a) sodium leberated reacts with water to produce NaOH+H2

(b) sodium being more electropositive than hydrogen, H2 is liberated at cathod and not sodium

(c) electrolysis cannot take place with brine solution

(d) none of the above

(b) It is a reason for given fact.

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