Sheet Chemistry

CHEMISTRY

BY : NAGENDRA SINGH

(SALT ANALYSIS)

(B.Tech IT. BHU)

COACHING 1.

Mob: 993595733

Two Two sol solid id labo labora rato tory ry reag reagen ents ts ‘A’ ‘A’ and and ‘B’ ‘B’ giv givee the the foll follow owin ing g rea react ctio ions ns : Co!"o#$% A : (i) On strongly heating it gives two oxides of sl!hr (ii) On adding a"eos #aO$ soltion to its a"eos soltion a dirty green !reci!itate is obtained% which starts trning brown on ex!osre to air. Co!"o#$% B : (iii) &t i'!arts green color to the fla'e (iv) &ts soltion does not give a !reci!itate on !assing $ 

(v) *hen it is heated with solid - ,r O +  and concentrated $ O %  a red gas is evolved. The gas when &Roo'ee 993*  !assed in an a"eos soltion of #aO$% trns it yellow. .

A ligh lightt gree green n cry crystal stalli line ne co' co'!o !on nd d res res!o !ond ndss to the the foll follow owin ing g test test : (i) &ts a"eos soltion gives a brown !reci!itate or coloration with al/aline - $g& soltion. (ii) &ts a"eos soltion gives a ble color with - 12e(,# ) 0  soltion. (iii) &ts soltion in hydrochloric acid gives a white !reci!itate with Ba,l  soltion. &dentify the ions &I.I.T. 99+*  !resent and sggest the for'la of the co'!ond.

.

An a"e a"eo oss sol solt tio ion n of of gas gas (3) (3) sho shows ws the the fol follo lowi wing ng reac reacti tion onss : (i) &t trns red lit's ble (ii) *hen added in excess to a co!!er sl!hate soltion% a dee! ble color is obtained. (iii) On addition of 2e,l  soltion% a brown !reci!itate% solble in dilte $#O  is obtained. &Roo'ee 99* &dentify (3) and give e"ations for the reactions at ste! (ii) and (iii).

.

A cert certai ain n co'! co'!o ond nd (3) (3) is sed sed in labo labora rato tory ry for for anal analys ysis is%% its its a"e a"eo oss sol solti tion on give givess the the follo followi wing ng reactions : (i) On adding co!!er sl!hate% a brown !reci!itate is obtained which trns white on addition of excess of  #a O1  soltion. (ii) On addition of Ag 4 ion soltion a yellow crdy !reci!itate is obtained which is insolble in a''oni' hydroxide. hydroxide. &Roo'ee 99* &dentify (3) and give e"ations for the reactions at ste! (i) and (ii).

5.

A co'!o co'!on nd d on heat heatin ing g with with an exc exces esss of cas casti ticc soda soda solt soltio ion n liber liberat ates es a gas gas (B) whic which h gives gives whit whitee f'es on ex!osre of $,l. $eating $eating it contined contined to ex!el the gas co'!letely. co'!letely. The resltant resltant al/aline soltion again liberates the sa'e gas (B) when heated with 6inc !owder. $owever the co'!ond (A)% when heated alone does not give nitrogen. &dentify (A) and (B).

0.

An

n/nown

solid

'ixtre

contains

one

or

two

of

the

following

:

,a,O1 % Ba,l  % Ag#O   1 %  #a O  % 7nO   and #aO$. The 'ixtre is co'!letely solble in

water and the soltion gives !in/ color with !henol!hthalein. *hen dilte hydrochloric acid is gradally added to above soltion% a !reci!itate is for'ed which dissolves with frther addition of the acid. *hat is8are !resent in the solid9 ive e"ations to ex!lain the a!!earance of the !reci!itate and its dissoltion. +.

The gas gas liber liberate ated d on heatin heating g a 'ixtr 'ixtree of of two two salts salts with with #aO$% #aO$% gives gives a redd reddish ish brown brown !reci! !reci!ita itate te with with an an al/aline soltion of -  $g& . The a"eos soltion of 'ixtre on treat'ent with Ba,l  gives a white  !reci!itate which is s!aringly solble in conc. $,l. On heating the 'ixtre with - ,r O +  and conc. $O% red va!!ors (A) are !rodced. The a"eos a"eos soltion of 'ixtre gives a dee! ble coloration (B) with !otassi' ferricyanide. &dentify the radicals in given 'ixtre and write the balanced e"ation for for'ation of (A) and (B).

&I.I.T. 99*

;.

A colorless solid (A) liberates a brown gas (B) on acidification% a colorless al/aline gas (,) on treat'ent with #aO$% and a colorless