Question

Name the gas that
(i) Does not affects filter paper dipped is acidified KMnO₄
(ii) Turns moist starch iodide paper blue black
(iii) Decolourises acidified KMnO₄ solution
(iv) Turns colourless PbNO3 solution into black

Answer 1

I) CO2

Carbon dioxide gas does not affect the filter dipped in acidified KmNO4.

II) Cl

Chlorine turns moist starch iodide paper blue-black because the iodide ions on the paper are oxidised to iodine and the starch reacta to give a blue black compound.

III) SO2

The sulphur dioxide gas changes the colour of acidified KmNO4 from purple to colourless.

IV) H2S

Hydrogen sulphide gas when passed through a lead nitrate solution gives a black precipitate.