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SUMMARY – ➢ Gases – neutral, acidic, basic, identification of gases – H₂, O₂, H₂O, CO₂, SO₂, Cl₂, HCl, H₂S, NH₃. ➢ Heating effect on different substances - PbO₂, CuCO₃, ZnCO₃, Na₂CO₃.10H₂O, CuSO₄.5H₂O, NH₄Cl. ➢ Identification of cations by NaOH and NH₄OH solution – Fe2+, Fe3+, Cu2+, Ca2+, Zn2+, Pb2+. ➢ Identification of anions :– CO32-, SO32-, S2-, SO42-, Cl-, NO3-. SECTION -1 1.
Identify the nature of the gas (acidic, basic, neutral ) : (i) Sulphur dioxide (ii) Carbon dioxide (iii) Ammonia (iv) Hydrogen chloride (v) Water vapour (vi) Oxygen (vii) Hydrogen (viii) Hydrogen sulphide
2.
Write the observation and a balanced equation when the following substances are heated. (a) Lead dioxide. (b) Copper carbonate. (c) Zinc carbonate. (d) Ammonium chloride.
3.
Fill in the blanks: (a) Zinc carbonate on heating leaves a residue which is _________ (white/yellow) when hot. (b) (sodium/ammonium)________________chloride on heating sublimes. (c) Sodium ____________ (nitrate, sulphate) reacts with barium chloride to give a white precipitate. (d) (carbon dioxide ,sulphur dioxide)______________turns lime water milky and K2Cr2O7 paper from orange to green.
SECTION-2 4.
Identify the following substances : (a) An alkaline gas A which gives dense white fumes with hydrogen chloride. (b) Gas C has an offensive smell like rotten eggs. (c) Gas D is a colourless gas which can be used as a bleaching agent.
5.
Name the gas which – (a) Turns moist starch iodine paper blue black. (b) Turns lead acetate paper silvery black. (c) Do not affect the acidified K₂Cr₂O₇ paper but turn lime water milky. (d) Affects the acidified K₂Cr₂O₇ paper and also turns lime water milky.
6.
What would you observe when dil. HCl is added to :
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