Bromine vapours turn starch iodide paper
(a) violet (b) blue
(c) yellow (d) red
A mixture when heated with dil. H2SO4 does not evolve brown vapours but when heated
with conc. H2SO4, brown vapours are obtained. The vapours when brought in contact
with silver nitrate solution do not give any precipitate. The mixture contains
(a) NO2
(b) NO3
(c) Cr (d) Br–
Ammonium dichromate is used in some fireworks. The green coloured powder blown in
air is due to
(a) CrO3 (b) Cr2O3
(c) Cr (D) CrO(O2)
A mixture, on heating with conc. H2SO4 and MnO2, liberates brown vapours of
(a) Br2 (b) NO2
(c) HBr (d) I2
A white solid is first heated with dil. H2SO4 and then with conc.H2SO4. No action was
observed in either case. The solid salt contains
(a) sulphide (b) sulphite
(c) thiosulphate (d) sulphate
An inorganic salt when heated evolves a coloured gas which bleaches moist litmus paper.
The evolved gas is
(a) NO2 (b) Cl2
(c) Br2 (d) I2
Which of the following metal oxides is white in colour but becomes yellow in heating?
(a) AgO (b) Ag2O
(c) FeO (d) ZnO
Which compound does not dissolve in hot dil. HNO3?
(a) HgS (b) PbS
(c) CuS (d) Cds
An aqueous solution of FeSO4.Al2(SO4)3 and chrome alum is heated with excess of
Na2SO3 and filtered. The materials obtained are
(a) a colourless filtrate and a green residue (b) a yellow filtrate and a green residue
(c) a yellow filtrate and a brown residue (d) a green filtrate and a brown residue
Magnesium carbonate does not precipitate with the carbonates of group V radicals in
presence of NH4OH and NH4Cl because
(a) MgCO3 is soluble in water (b) MgCO3 is soluble in NH4OH
(c) MgCO3 is soluble in NH4Cl (d) MgCO3 is soluble in (NH4)2CO3
When H2S is passed through an ammonia salt solution X, a white precipitate is obtained.
The X can be
(a) cobalt salt (b) nickel salt
(c) manganese salt (d) zinc salt
The best explanation for the solubility of MnS in dil. HCl in salt
(a) solubility product of MnCl2 is less than that of MnS
(b) concentration of Mn2+ is lowered by the formation of complex ions with chloride ions.
(c) concentration of sulphide ions is lowered by oxidation to free sulphur.
(d) concentration of sulphide ions is lowered by formation of the weak acid H2S.
H2S gas is passed into aqueous solution of Zn(CH3COO)2 and ZnCl2 in test tubes I and II
separately. Then ZnS is precipitated :
(a) in I (b) in II
(c) in both (d) in none of these
Which of the following metals can liberate hydrogen on reacting with dilute hydrochloric
acid :
(a) Cu (b) Zn
(c) Mg (d) Fe
When oxalic acid is heated with conc. H2SO4, it produces:
(a) CO (b) CO2
(c) SO2 (d) SO3
Iodine imparts brown colour to :
(a) Water (b) Ether
(c) Alcohol (d) Chloroform
Hydrogen iodide cannot be made by the action of concentrated sulphuric acid on
potassium iodide because :
(a) H2SO4 in an oxidizing agent (b) HI is stronger acid than H2SO4
(c) HI is strong reducing agent (d) H2SO4 is stronger acid then HI
16. Which is following is/are insoluble in yellow ammonium sulphide
(a) CuS (b) SnS
(c) HgS
18. A light green coloured salt soluble in water gives black precipitate on passing H2S which dissolves readily in HCl. The metal ion present is:
20. Two test tubes containing a nitrate and a bromides are treated separately with H2SO4 ; brown fumes evolved are passed in water. The water will be coloured by vapours evolved from the test tube containing.
(a) Nitrate (b) Bromide
(c) both (a) and (b) (d) none of these
21. A white salt is insoluble in cold water but soluble in boiling water. Its solution when treated with potassium chromate solution gives yellow precipitate. The salt may be :
22. A white powder when strongly heated gives off brown fumes. a solution of this powder gives as yellow precipitate with a solution of KI. When a solution of barium chloride is added to a solution of powder, a white precipitate results. This white powder may be :
23. A reddish-pink substance on heating gives off a vapour which condenses on the sides of the test tube and the substance turns blue. If on cooling water is added to the residue it turns to its original colour. The substance is :
(a) Iodine crystals (b) Copper sulphate crystals
(c) Cobalt chloride crystals (d) Zinc oxide
25. The solution of a chemical compound X reacts with AgNO3 solution to from a white precipitate of Y which dissolves in NH4OH to give a complex Z. When Z is treated with dilute HNO3, Y reappears. The chemical compound X can be :