Among the following compounds, the one(s) that gives (give) effervescence with aqueous NaHCO₃ solution is (are)

(CH₃CO)₂ O           CH₃COOH         PhOH          CH₃COCHO

   I                           II                   III                 IV

• I and II

• I and III

• Only II

• I and IV

Chlorine gas reacts with red hot calcium oxide to give

• bleaching powder and dichlorine monoxide

• bleaching powder and water

• calcium chloride and chlorine dioxide

• calcium chloride and oxygen

The reaction of nitroprusside anion with sulphide ion gives purple colouration due to the formation of

• the tetranionic complex of iron (II) coordinating to one NOS^- ion

• the dianoinic complex of iron (II) coordinating to one NCS^- ion

• the trianoionic complex of iron (III) coordinating to one NOS^- ion

• the tetranionic complex of iron (III) coordinating to one NCS^- ion

An amorphous solid (X) burns in air to form a gas (Y) which turns lime water milky. This gas decolarises aqueous solution of acidified KMnO₄ gas (Y)reacts with oxygen to give another gas (Z) which is responsible for acid rain. X, Y and Z are

• X	Y	Z
  C	CO	CO2

• X	Y	Z
  S	SO2	SO3

• X	Y	Z
  P	P2O3	P2O5

• X	Y	Z
  S	SO3	H2SO4

A black power when heated with conc. HCl gives a greenish yellow gas. The gas acts as an oxidising and a bleaching agent. When it is passed are slaked lime, a white power is formed which is a ready source of gas. The black powder and white power respectively are

• KClO₃ and NaClO₃

• MnO₂ and CaCOCl₂

• MnO₂ and KClO₃

• MnCl₄ and COCl₂

Which of the following is an organometallic compound?

• Lithium methoxide

• Lithium acetate

• Lithium dimethylamide

• Methyl lithium

A compound X on heating gives a colourless gas. The residue is dissolved in water to obtain Y. Excess CO₂ is passed through aqueous solution of Y when Z is formed. Z on gentle heating gives back X. The compound X is

• Ca(HCO₃)₂

• CaCO₃

• NaHCO₃

• Na₂CO₃

18.

With excess of water, both P₂O₅ and PCl₅ give

• H₃PO₃

• H₃PO₂

• H₃PO₄

• H₄P₂O₇

Which sequence of reactions shows correct chemical relation between sodium and its compounds?

• $\mathrm{Na} + {\mathrm{O}}_2 \to {\mathrm{Na}}_2\mathrm{O} \stackrel{\mathrm{HCl}\left(\mathrm{aq}\right)}{\to }\mathrm{NaCl}\stackrel{{\mathrm{CO}}_2}{\to }{\mathrm{Na}}_2{\mathrm{CO}}_3\stackrel{∆}{\to }\mathrm{Na}$

• $\mathrm{Na}\stackrel{{\mathrm{O}}_2}{\to }{\mathrm{Na}}_2\mathrm{O}\stackrel{{\mathrm{H}}_2\mathrm{O}}{\to }\mathrm{NaOH}\stackrel{{\mathrm{CO}}_2}{\to }{\mathrm{Na}}_2{\mathrm{CO}}_3\stackrel{∆}{\to }\mathrm{Na}$

• $\mathrm{Na}+{\mathrm{H}}_2\mathrm{O} \to \mathrm{NaOH}\stackrel{\mathrm{HCl}}{\to }\mathrm{NaCl}\stackrel{{\mathrm{CO}}_2}{\to }{\mathrm{Na}}_2{\mathrm{CO}}_2\stackrel{∆}{\to }\mathrm{Na}$

• $\mathrm{Na}+{\mathrm{H}}_2\mathrm{O} \to \mathrm{NaOH} \stackrel{{\mathrm{CO}}_2}{\to }{\mathrm{Na}}_2{\mathrm{CO}}_3\stackrel{\mathrm{HCl}}{\to }\underset{\left(\mathrm{molten}\right)}{\mathrm{NaCl}} \stackrel{\mathrm{Electrolysis}}{\to }\mathrm{Na}$

The sodium extract of an organic compound on acidification with acetic acid and addition of lead acetate solution gives a black precipitate. The organic compound contains

• nitrogen

• halogen

• sulphur

• phosphorus