Page 1
Class X Chapter-4 – Analytical Chemistry Chemistry
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EXERCISE- 1 (A)
Question 1:
Write the probable colour of the following salts.
(a) Ferrous salts
(b) Ammonium salts
(c) Cupric salts
(d) Calcium salts
(e) Aluminium Salts
Solution 1:
(a) Ferrous salts : Light green
(b) Ammonium salts : Colourless
(c) Cupric salts : Blue
(d) Calcium salts : Colourless
(e) Aluminium salts : Colourless
Question 2:
Name:
(a) a metallic hydroxide soluble in excess of NH4OH.
(b) a metallic oxide solube in excess of caustic soda solution.
(c) a strong alkali
(d) a weak alkali
(e) two coloured metal ions
(f) two coloured metal ions
(g) a metal that evolves a gas which burns with a pop sound when boiled with alkali solutions.
(h) two bases which are not alkalis but dissolves in alkalis to yield colourless solutions.
(j) a coloured cation not a representative element.
Solution 2:
(a) Cu(OH)2
(b) ZnO
(c) NaOH
(d) NH4OH
(e) Na
+
, Ca
2+
(f) Fe
2+
, Mn
2+
(g) Aluminium
Page 2
Class X Chapter-4 – Analytical Chemistry Chemistry
______________________________________________________________________________
EXERCISE- 1 (A)
Question 1:
Write the probable colour of the following salts.
(a) Ferrous salts
(b) Ammonium salts
(c) Cupric salts
(d) Calcium salts
(e) Aluminium Salts
Solution 1:
(a) Ferrous salts : Light green
(b) Ammonium salts : Colourless
(c) Cupric salts : Blue
(d) Calcium salts : Colourless
(e) Aluminium salts : Colourless
Question 2:
Name:
(a) a metallic hydroxide soluble in excess of NH4OH.
(b) a metallic oxide solube in excess of caustic soda solution.
(c) a strong alkali
(d) a weak alkali
(e) two coloured metal ions
(f) two coloured metal ions
(g) a metal that evolves a gas which burns with a pop sound when boiled with alkali solutions.
(h) two bases which are not alkalis but dissolves in alkalis to yield colourless solutions.
(j) a coloured cation not a representative element.
Solution 2:
(a) Cu(OH)2
(b) ZnO
(c) NaOH
(d) NH4OH
(e) Na
+
, Ca
2+
(f) Fe
2+
, Mn
2+
(g) Aluminium
Class X Chapter-4 – Analytical Chemistry Chemistry
______________________________________________________________________________
(h) Zn(OH)2 and Al(OH)3
(i) PbO
(j) Ammonium ion
Question 3:
Write balanced equations for Q.2 (g) and (i)
Solution 3:
2Al + 2NaOH + 2H2O ? 2NaAlO2 + 3H2
(Hot and conc.) Sodium meta aluminate
(colourless)
PbO + 2NaOH ? Na2PbO2 + H2O
(Yellow) sodium plumbate
(colourless, soluble)
Question 4:
What happens when ammonia solution is added first dropwise and then in excess to the
following solution:
(i) CuSO4 (ii) ZnSO4 (iii) FeCI3
Write balanced equations for these reactions.
Solution 4:
(i)
CuSO4 + 2NH4OH ? Cu(OH)2 ? (NH4)2 SO4
Blue pale blue ppt. colourless is solution
With excess of NH4OH, ppt dissolves
CU(OH)2 + (NH4)2SO4 + 2NH4OH ? [Cu(NH3)4]SO4 + 4H2O
Excess Tetrammine
Copper(II) Sulphate
(ii)
ZnSO4 + 2NH4OH ? Zn(OH)2 + (NH4)2 SO4
Colourless white, gelatinous ppt colourless
With excess of NH4OH, ppt dissolves
Zn(OH)2 + (NH4)2SO4 + 2NH4OH ? [Zn(NH3)4]SO4 + 4H2O
(excess) Tetramminezinc(II) Sulphate
(colourless)
Page 3
Class X Chapter-4 – Analytical Chemistry Chemistry
______________________________________________________________________________
EXERCISE- 1 (A)
Question 1:
Write the probable colour of the following salts.
(a) Ferrous salts
(b) Ammonium salts
(c) Cupric salts
(d) Calcium salts
(e) Aluminium Salts
Solution 1:
(a) Ferrous salts : Light green
(b) Ammonium salts : Colourless
(c) Cupric salts : Blue
(d) Calcium salts : Colourless
(e) Aluminium salts : Colourless
Question 2:
Name:
(a) a metallic hydroxide soluble in excess of NH4OH.
(b) a metallic oxide solube in excess of caustic soda solution.
(c) a strong alkali
(d) a weak alkali
(e) two coloured metal ions
(f) two coloured metal ions
(g) a metal that evolves a gas which burns with a pop sound when boiled with alkali solutions.
(h) two bases which are not alkalis but dissolves in alkalis to yield colourless solutions.
(j) a coloured cation not a representative element.
Solution 2:
(a) Cu(OH)2
(b) ZnO
(c) NaOH
(d) NH4OH
(e) Na
+
, Ca
2+
(f) Fe
2+
, Mn
2+
(g) Aluminium
Class X Chapter-4 – Analytical Chemistry Chemistry
______________________________________________________________________________
(h) Zn(OH)2 and Al(OH)3
(i) PbO
(j) Ammonium ion
Question 3:
Write balanced equations for Q.2 (g) and (i)
Solution 3:
2Al + 2NaOH + 2H2O ? 2NaAlO2 + 3H2
(Hot and conc.) Sodium meta aluminate
(colourless)
PbO + 2NaOH ? Na2PbO2 + H2O
(Yellow) sodium plumbate
(colourless, soluble)
Question 4:
What happens when ammonia solution is added first dropwise and then in excess to the
following solution:
(i) CuSO4 (ii) ZnSO4 (iii) FeCI3
Write balanced equations for these reactions.
Solution 4:
(i)
CuSO4 + 2NH4OH ? Cu(OH)2 ? (NH4)2 SO4
Blue pale blue ppt. colourless is solution
With excess of NH4OH, ppt dissolves
CU(OH)2 + (NH4)2SO4 + 2NH4OH ? [Cu(NH3)4]SO4 + 4H2O
Excess Tetrammine
Copper(II) Sulphate
(ii)
ZnSO4 + 2NH4OH ? Zn(OH)2 + (NH4)2 SO4
Colourless white, gelatinous ppt colourless
With excess of NH4OH, ppt dissolves
Zn(OH)2 + (NH4)2SO4 + 2NH4OH ? [Zn(NH3)4]SO4 + 4H2O
(excess) Tetramminezinc(II) Sulphate
(colourless)
Class X Chapter-4 – Analytical Chemistry Chemistry
______________________________________________________________________________
(iii)
FeCI3 + 3NH4OH ? Fe(OH)3 ? + 3NH4CI
Yellow solution reddish brown ppt. colourless in solution
Question 5:
What do you observe when caustic soda solution is added to the following solution, first a little
and then in excess:
(a) FeCI3
(b) ZnSO4
(c) Pb(NO3)2
(d) CuSO4
Write balanced equations for these reactions.
Solution 5:
(i) FeCI3 + 3NaOH ? Fe(OH)3 ? 3 NaCI
Yellow reddish brown, ppt colourless in solution
In excess of alkali, the reddish brown ppt, of Fe(OH)3 remains insoluble
(ii) ZnSO4 + 2NaOH ? Zn(OH)2 ? + NaSO4
Colourless white gelatinous ppt. colourless
In excess of alkali, white gelatinous ppt. of Zn(OH)2 becomes soluble
Zn(OH)2 + 2NaOH (Excess) ? Na2ZnO2 + 2H2O
Sodium zincate (colourless)
(iii) Pb(NO3)2 + 2NaOH ? Pb(OH)2 ? + 2NaNO3
White ppt (colourless)
In excess of alkali, white precipitate of Pb(OH)2 becom essoluble:
Pb(OH)2 + 2NaOH(excess) ? Na2PbO2 + 2H2O
Sodium plumbate
{colourless}
CuSO4 + 2NaOH ? Cu(OH)2 ? + 2NaSO4
Blue colourless pale blue ppt. { colourless}
In excess of alkali, pale blue precipitate of Cu(OH)2 is insoluble
Page 4
Class X Chapter-4 – Analytical Chemistry Chemistry
______________________________________________________________________________
EXERCISE- 1 (A)
Question 1:
Write the probable colour of the following salts.
(a) Ferrous salts
(b) Ammonium salts
(c) Cupric salts
(d) Calcium salts
(e) Aluminium Salts
Solution 1:
(a) Ferrous salts : Light green
(b) Ammonium salts : Colourless
(c) Cupric salts : Blue
(d) Calcium salts : Colourless
(e) Aluminium salts : Colourless
Question 2:
Name:
(a) a metallic hydroxide soluble in excess of NH4OH.
(b) a metallic oxide solube in excess of caustic soda solution.
(c) a strong alkali
(d) a weak alkali
(e) two coloured metal ions
(f) two coloured metal ions
(g) a metal that evolves a gas which burns with a pop sound when boiled with alkali solutions.
(h) two bases which are not alkalis but dissolves in alkalis to yield colourless solutions.
(j) a coloured cation not a representative element.
Solution 2:
(a) Cu(OH)2
(b) ZnO
(c) NaOH
(d) NH4OH
(e) Na
+
, Ca
2+
(f) Fe
2+
, Mn
2+
(g) Aluminium
Class X Chapter-4 – Analytical Chemistry Chemistry
______________________________________________________________________________
(h) Zn(OH)2 and Al(OH)3
(i) PbO
(j) Ammonium ion
Question 3:
Write balanced equations for Q.2 (g) and (i)
Solution 3:
2Al + 2NaOH + 2H2O ? 2NaAlO2 + 3H2
(Hot and conc.) Sodium meta aluminate
(colourless)
PbO + 2NaOH ? Na2PbO2 + H2O
(Yellow) sodium plumbate
(colourless, soluble)
Question 4:
What happens when ammonia solution is added first dropwise and then in excess to the
following solution:
(i) CuSO4 (ii) ZnSO4 (iii) FeCI3
Write balanced equations for these reactions.
Solution 4:
(i)
CuSO4 + 2NH4OH ? Cu(OH)2 ? (NH4)2 SO4
Blue pale blue ppt. colourless is solution
With excess of NH4OH, ppt dissolves
CU(OH)2 + (NH4)2SO4 + 2NH4OH ? [Cu(NH3)4]SO4 + 4H2O
Excess Tetrammine
Copper(II) Sulphate
(ii)
ZnSO4 + 2NH4OH ? Zn(OH)2 + (NH4)2 SO4
Colourless white, gelatinous ppt colourless
With excess of NH4OH, ppt dissolves
Zn(OH)2 + (NH4)2SO4 + 2NH4OH ? [Zn(NH3)4]SO4 + 4H2O
(excess) Tetramminezinc(II) Sulphate
(colourless)
Class X Chapter-4 – Analytical Chemistry Chemistry
______________________________________________________________________________
(iii)
FeCI3 + 3NH4OH ? Fe(OH)3 ? + 3NH4CI
Yellow solution reddish brown ppt. colourless in solution
Question 5:
What do you observe when caustic soda solution is added to the following solution, first a little
and then in excess:
(a) FeCI3
(b) ZnSO4
(c) Pb(NO3)2
(d) CuSO4
Write balanced equations for these reactions.
Solution 5:
(i) FeCI3 + 3NaOH ? Fe(OH)3 ? 3 NaCI
Yellow reddish brown, ppt colourless in solution
In excess of alkali, the reddish brown ppt, of Fe(OH)3 remains insoluble
(ii) ZnSO4 + 2NaOH ? Zn(OH)2 ? + NaSO4
Colourless white gelatinous ppt. colourless
In excess of alkali, white gelatinous ppt. of Zn(OH)2 becomes soluble
Zn(OH)2 + 2NaOH (Excess) ? Na2ZnO2 + 2H2O
Sodium zincate (colourless)
(iii) Pb(NO3)2 + 2NaOH ? Pb(OH)2 ? + 2NaNO3
White ppt (colourless)
In excess of alkali, white precipitate of Pb(OH)2 becom essoluble:
Pb(OH)2 + 2NaOH(excess) ? Na2PbO2 + 2H2O
Sodium plumbate
{colourless}
CuSO4 + 2NaOH ? Cu(OH)2 ? + 2NaSO4
Blue colourless pale blue ppt. { colourless}
In excess of alkali, pale blue precipitate of Cu(OH)2 is insoluble
Class X Chapter-4 – Analytical Chemistry Chemistry
______________________________________________________________________________
Question 6:
Name the chloride of a metal which is soluble in excess of ammonium hydroxide. Write equation
for the same.
Solution 6:
Zinc chloride (ZnCl2) is soluble in excess of ammonium hydroxide.
ZnCI2 + 2NH4OH ? Zn(OH)2 ? 2NH4CI
Colourless White gelatinous ppt.
With excess of NH4oh ppt dissolves
Zn(OH)2 + 2NH4CI + 2NH4OH (excess) ? [Zn(NH3)4]CI2 + 4H2O
Tetram mine zinc (II) Chloride
Colourless
Question 7:
On adding dilute ammonia solution to a colourless solution of a salt, a white gelatinous
precipitate appears. This precipitate however dissolves on addition of excess of ammonia
solution identify (choose from Na, Al, Zn, Pb, Fe)
(a) Which metal salt solution was used?
(b) what is the formula of the white gelatinous precipitate obtained?
Solution 7:
(a) ZnCl2
(b) Zn(OH)2
Question 8:
Name:
(a) a yellow monoxide that dissolves in hot and concentrated caustic alkali
(b) a white, insoluble oxide that dissolves when fused with caustic soda or caustic potash
(c) a compound containing zinc in the anion
Solution 8:
(a) PbO
(b) ZnO
(c) K2ZnO2
Page 5
Class X Chapter-4 – Analytical Chemistry Chemistry
______________________________________________________________________________
EXERCISE- 1 (A)
Question 1:
Write the probable colour of the following salts.
(a) Ferrous salts
(b) Ammonium salts
(c) Cupric salts
(d) Calcium salts
(e) Aluminium Salts
Solution 1:
(a) Ferrous salts : Light green
(b) Ammonium salts : Colourless
(c) Cupric salts : Blue
(d) Calcium salts : Colourless
(e) Aluminium salts : Colourless
Question 2:
Name:
(a) a metallic hydroxide soluble in excess of NH4OH.
(b) a metallic oxide solube in excess of caustic soda solution.
(c) a strong alkali
(d) a weak alkali
(e) two coloured metal ions
(f) two coloured metal ions
(g) a metal that evolves a gas which burns with a pop sound when boiled with alkali solutions.
(h) two bases which are not alkalis but dissolves in alkalis to yield colourless solutions.
(j) a coloured cation not a representative element.
Solution 2:
(a) Cu(OH)2
(b) ZnO
(c) NaOH
(d) NH4OH
(e) Na
+
, Ca
2+
(f) Fe
2+
, Mn
2+
(g) Aluminium
Class X Chapter-4 – Analytical Chemistry Chemistry
______________________________________________________________________________
(h) Zn(OH)2 and Al(OH)3
(i) PbO
(j) Ammonium ion
Question 3:
Write balanced equations for Q.2 (g) and (i)
Solution 3:
2Al + 2NaOH + 2H2O ? 2NaAlO2 + 3H2
(Hot and conc.) Sodium meta aluminate
(colourless)
PbO + 2NaOH ? Na2PbO2 + H2O
(Yellow) sodium plumbate
(colourless, soluble)
Question 4:
What happens when ammonia solution is added first dropwise and then in excess to the
following solution:
(i) CuSO4 (ii) ZnSO4 (iii) FeCI3
Write balanced equations for these reactions.
Solution 4:
(i)
CuSO4 + 2NH4OH ? Cu(OH)2 ? (NH4)2 SO4
Blue pale blue ppt. colourless is solution
With excess of NH4OH, ppt dissolves
CU(OH)2 + (NH4)2SO4 + 2NH4OH ? [Cu(NH3)4]SO4 + 4H2O
Excess Tetrammine
Copper(II) Sulphate
(ii)
ZnSO4 + 2NH4OH ? Zn(OH)2 + (NH4)2 SO4
Colourless white, gelatinous ppt colourless
With excess of NH4OH, ppt dissolves
Zn(OH)2 + (NH4)2SO4 + 2NH4OH ? [Zn(NH3)4]SO4 + 4H2O
(excess) Tetramminezinc(II) Sulphate
(colourless)
Class X Chapter-4 – Analytical Chemistry Chemistry
______________________________________________________________________________
(iii)
FeCI3 + 3NH4OH ? Fe(OH)3 ? + 3NH4CI
Yellow solution reddish brown ppt. colourless in solution
Question 5:
What do you observe when caustic soda solution is added to the following solution, first a little
and then in excess:
(a) FeCI3
(b) ZnSO4
(c) Pb(NO3)2
(d) CuSO4
Write balanced equations for these reactions.
Solution 5:
(i) FeCI3 + 3NaOH ? Fe(OH)3 ? 3 NaCI
Yellow reddish brown, ppt colourless in solution
In excess of alkali, the reddish brown ppt, of Fe(OH)3 remains insoluble
(ii) ZnSO4 + 2NaOH ? Zn(OH)2 ? + NaSO4
Colourless white gelatinous ppt. colourless
In excess of alkali, white gelatinous ppt. of Zn(OH)2 becomes soluble
Zn(OH)2 + 2NaOH (Excess) ? Na2ZnO2 + 2H2O
Sodium zincate (colourless)
(iii) Pb(NO3)2 + 2NaOH ? Pb(OH)2 ? + 2NaNO3
White ppt (colourless)
In excess of alkali, white precipitate of Pb(OH)2 becom essoluble:
Pb(OH)2 + 2NaOH(excess) ? Na2PbO2 + 2H2O
Sodium plumbate
{colourless}
CuSO4 + 2NaOH ? Cu(OH)2 ? + 2NaSO4
Blue colourless pale blue ppt. { colourless}
In excess of alkali, pale blue precipitate of Cu(OH)2 is insoluble
Class X Chapter-4 – Analytical Chemistry Chemistry
______________________________________________________________________________
Question 6:
Name the chloride of a metal which is soluble in excess of ammonium hydroxide. Write equation
for the same.
Solution 6:
Zinc chloride (ZnCl2) is soluble in excess of ammonium hydroxide.
ZnCI2 + 2NH4OH ? Zn(OH)2 ? 2NH4CI
Colourless White gelatinous ppt.
With excess of NH4oh ppt dissolves
Zn(OH)2 + 2NH4CI + 2NH4OH (excess) ? [Zn(NH3)4]CI2 + 4H2O
Tetram mine zinc (II) Chloride
Colourless
Question 7:
On adding dilute ammonia solution to a colourless solution of a salt, a white gelatinous
precipitate appears. This precipitate however dissolves on addition of excess of ammonia
solution identify (choose from Na, Al, Zn, Pb, Fe)
(a) Which metal salt solution was used?
(b) what is the formula of the white gelatinous precipitate obtained?
Solution 7:
(a) ZnCl2
(b) Zn(OH)2
Question 8:
Name:
(a) a yellow monoxide that dissolves in hot and concentrated caustic alkali
(b) a white, insoluble oxide that dissolves when fused with caustic soda or caustic potash
(c) a compound containing zinc in the anion
Solution 8:
(a) PbO
(b) ZnO
(c) K2ZnO2
Class X Chapter-4 – Analytical Chemistry Chemistry
______________________________________________________________________________
Question 9:
What do you observe when freshly precipitated aluminium hydroxide reacts with caustic soda
solution? Give balanced equation.
Solution 9:
(a) (iii)
Aqueous solution of copper sulphate is blue.
(b) (iii)
FeSO4 + 2NaOH ? Fe(OH)2 + Na2SO4
(Dirty green, (Colourless)
gelatinous ppt.)
(c) (iii)
Zn + 2NaOH ? Na2ZnO2 + H2
Sodium zincate
(Colourless)
Zz Zn + HCl ? ZnCl2 + H2
Question 10:
What do you understand by amphoteric oxide Give the balanced equations for the reaction with
three different amphoteric oxides with a caustic alkali. Write you observation if any.
Solution 10:
When freshly precipitated aluminum hydroxide reacts with caustic soda solution, whitesalt of
sodium meta aluminate is obtained.
Al(OH)3 + NaOH ? NaAlO2 + 2H2O
Sodium meta aluminate
Question 11:
Distinguish by adding:
(a) sodium hydroxide solution and
(b) Ammonium hydroxide solution to
(i) Calcium salt solution and lead salt solution
(ii) Lead salt solution and ferrous salt solution
(iii) copper salt solution and ferrous salt solution
(iv) Fe (II) salt solution and Fe (III) Salt solution
(v) Ferrous nitrate and lead nitrate
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