(a) Gas ‘A’ is obtained by dehydration of ethanol. It undergoes complete combustion to form carbon dioxide and water.
(i) Identify gas ‘A’.
(ii) Give balanced chemical equation for the reaction.
(iii) What volume of carbon dioxide is produced by burning 50cm3 of gas ‘A’ in oxygen?
(iv) Name the law applied in solving the above problem.
(b) AgNO3 + NaCl AgCl + NaNO3
How many grams of silver nitrate are required to precipitate 287g of silver chloride?
(N=14, O=16, Cl=35.5, Ag=108)
(c) If a compound has empirical formula CH2O and its molecular weight is 180, calculate its molecular formula. [4+3+3]
(b) AgNO3 + NaCl AgCl + NaNO3
(a) Name the following:
(i)The flame used for welding and cutting metals
(ii)The gas commonly called marsh gas
(iii) The gas which decolourises bromine solution in carbon tetrachloride and gives white precipitate with ammonical silver nitrate
(iv) First organic compound synthesised in laboratory
(v)The property of carbon by which its atoms can link to form long chains or ring type structures
(b) Write balanced chemical equations for the following:
(i) Burning of ethane in sufficient supply of air
(ii) Aluminium carbide is hydrolysed.
(iii) Ethyl chloride reacts with aqueous potassium hydroxide.
(iv) Ethanol reacts with acetic acid in presence of conc. sulphuric acid.
(v) Acetylene is passed through red hot copper tube. 
(i) Oxy acetylene flame
(i) Acid salt
(ii) Diprotic acid
(iv) Double salt
(b) How does barium chloride solution help in distinguishing between zinc nitrate and zinc sulphate solution?
(c) Name the suitable method by which you could prepare soluble salt like sodium chloride and an insoluble salt like lead sulphate.
(i) Acid salt – The salt formed by the partial or incomplete replacement of replaceable hydrogen ions of an acid by a basic radical or metallic ion.
(ii) Diprotic acid – An acid which gives two hydrogen ions on ionisation in solution is called diprotic acid.
(iii) Alkali – A base is called as alkali if it is highly soluble in water. In aqueous solution, an alkali gives hydroxide ions (OH–) as the only anion.
(iv) Double salt – A salt which is formed by the combination of two simple salts in their saturated solutions is called as double salt.
(v) Neutralisation – When hydrogen ions derived from an acid and hydroxyl ions derived from the base are combined to form unionised water molecule, the reaction is called as neutralisation reaction.
(vi) Acid – These are chemical compounds which on dissolving in water, produce hydrogen ions or hydronium ions as the only positively charged particles.
(b) Barium chloride solution on reaction with zinc nitrate, gives no visible reaction.
BaCl2 + Zn(NO3)2 → Ba(NO3)2 + ZnCl2
On the contrary, barium chloride solution on reaction with zinc sulphate gives a white precipitate which is insoluble in all the mineral acids.
BaCl2 + ZnSO4 → BaSO4 + ZnCl2
(c) Sodium chloride (soluble salt) – Neutralisation
Lead sulphate (insoluble salt) – Precipitation
(a) When ammonium salts (like ammonium chloride) are heated with an alkali (say sodium hydroxide) they produce gas ‘A’. With reference to certain properties of gas ‘A’ answer the following questions.
(i)Identify gas ‘A’.
(ii) Write balanced chemical equation for the reaction which produces gas ‘A’.
(iii) How is gas ‘A’ collected and dried?
(iv) What do you observe when gas ‘A’ is mixed with hydrogen chloride gas?
(b) Dilute nitric acid acts as a typical acid except for the reaction with metals. How does the action of nitric acid on metals varies from other dilute acids?
(c) Write balanced chemical equation for the preparation of nitric acid and hydrochloric acid in laboratory.
(d) Name two metallic nitrates, which on heating give respective metals, nitrogen dioxide (NO2) and oxygen (O2).
(i) Gas ‘A’ is ammonia.
(iii) Gas ‘A’ is collected by the downward displacement of air. It is dried by passing over quick lime (CaO).
(iv) Dense white fumes are observed.
(b) All dilute acids react with metals to liberate hydrogen but dilute nitric acid on reacting with metals does not produce hydrogen as it is a strong oxidising agent.
(d) Silver nitrate and mercuric nitrate
(a) Name the anhydride of sulphurous acid. Write balanced chemical equation for the laboratory preparation of this anhydride from:
(i) Salt and dilute sulphuric acid.
(ii) By roasting metallic sulphide
(iii)By reacting metal (copper) with concentrated sulphuric acid
(iv) By reacting non-metal (sulphur) with concentrated sulphuric acid
(b) Name the method by which sulphric acid is manufactured on industrial scale. This method is completed in many steps. Write balanced chemical equation for the reaction which takes place in the presence of the catalyst.
(c) Give one equation for each to show that the sulphuric acid acts as:
(i) Oxidising agent.
(ii) Dehydrating agent.
(iii) Non-volatile acid.
(b) Name of the process is contact process.
(i) Name the greenish yellow gas which is placed in Group 17 of modern periodic table. This gas is capable of displacing the other two halogens from their salt solutions. Give equations also.
(ii) Arrange the hydracids of Group 17 elements in the increasing order of their acidic strength.
(iii) Name the Group 17 element having highest electron affinity.
(b) Predict the types of bonds present in the following:
(i) Ammonium ion
(ii) Calcium oxide
(i) Chlorine (Cl2)
2KBr + Cl2 2KCl + Br2
2KI + Cl2 2KCl + I2
(a) Choose from the following list of substances the one which matches the description from (i) to (v) given below:
[Methane, Hydrogen chloride, Ammonia, Methanol, Hydrogen sulphide, Copper oxide, Lead bromide, Copper sulphate, Carbon dioxide, Propanol]
(i) A compound that is not a metal hydroxide but its aqueous solution is alkaline in nature.
(ii) A compound added to make drinking alcohol unfit for human consumption.
(iii) A compound that can be reduced to copper when heated with coke.
(iv) When this compound is electrolysed in the molten state, lead is obtained at the cathode.
(v) A compound that can be oxidised to chlorine.
(b) What would you observe in each of the following cases?
(i) Ammonium hydroxide is added to zinc nitrate solution, first in small amount and then in excess.
(ii)Ammonia gas is passed through conc. hydrochloric acid.
(iii)Nitric acid is kept in a reagent bottle for a long time.
(iv)Hydrochloric acid is added to silver nitrate solution.
(v) Concentrated sulphuric acid is added to crystals of hydrated copper sulphate (CuSO4.5H2O).
(c) Give reasons:
(i) Solid sodium chloride does not conduct electricity.
(ii) Bond formed in hydrogen molecule is non-polar covalent bond.
(iii) In the laboratory preparation of nitric acid, the mixture of concentrated sulphuric acid and sodium nitrate should not be heated very strongly above 200°C.
(iv) Noble gases have zero electron affinity.
(v) The ionization potential increases as we move across the period.
(d) Fill in the blanks from the choices given:
(i) The (higher/lower) ………………… the concentration of an ion in a solution, the lesser is the probability of its being discharged at the appropriate electrode.
(ii) Across a period, the metallic character ……………… (decreases/increases/remains same).
(iii) Alkenes are unsaturated hydrocarbons which undergo …………… reaction (addition/substitution).
(iv) Oxidising agents during the reaction get ……………….. (reduced/oxidised).
(v) Ammoniacal silver nitrate solution is ……………… (Fehling solution/Tollen’s reagent).
(i) State Avogadro’s law and give its two applications.
(ii) How many molecules are present in 2.2 grams of carbon dioxide (Avogadro’s number can be used as 6x1023)(M.wt. of CO2=44)? (iii) The volumes of two gases A and B are in the ratio of 1:2 under same conditions of temperature and pressure. If the volume of A is 5.6dm3 at STP, calculate the number of molecules in the actual volume of gas B at STP.
(f) Choose the correct answer from the options given below:
(i) Cinnabar is an ore of:
(ii) Passage of electric current through a metallic conductor results in
(A) physical change
(B) chemical change
(C) both physical and chemical change
(D) none of the above
(iii) The most electronegative element in second period is present in
(A) Group 17
(B) Group 1
(C) Group 13
(D) Group 18
(iv) Aluminium oxide is
(A) basic oxide
(B) amphoteric oxide
(C) acidic oxide
(D) neutral oxide
(v) Ammonia molecule contains
(A) three covalent bonds and two lone pairs of electrons
(B) two covalent bonds and three lone pairs of electrons
(C) three covalent bonds and one lone pair of electrons
(D) two covalent bonds and three lone pairs of electrons
(vi) Nitrogen oxide is a
(A) reddish brown gas
(B) colourless and odourless gas
(C) greenish yellow gas
(D) none of these
(vii) The catalyst used during the preparation of sulphuric acid by contact process is
(C) Phosphorus pentaoxide
(D) Vanadium pentoxide
(viii) The pair of gases which turn lime water milky is
(A) CO2 and SO3
(B) SO2 and SO3
(C) SO2 and CO2
(D) CO2 and NH3
(ix) But-1-ene and But-2-ene are the examples of
(A) position isomers
(B) functional isomers
(C) chain isomers
(D) stereo isomers
(x) The final oxidation product of primary alcohol is
(B) carboxylic acid
(g) Write a balanced chemical equation for each of the following reactions:
(i) Copper chips are treated with concentrated sulphuric acid.
(ii) Calcium carbide is hydrolysed.
(iii) Sulphur dioxide is passed through hydrogen sulphide solution.
(iv) Dilute sulphuric acid is added to lead nitrate solution. (v) Ammonia is passed over heated copper oxide.
(iii) Copper oxide
(iv) Lead bromide
(v) Hydrogen chloride
(i) On adding a small amount of ammonium hydroxide to zinc nitrate solution, white precipitate is formed which dissolves in excess of ammonium hydroxide to give a clear solution.
(ii)Dense white fumes of ammonium chloride are observed.
(iii) Brown vapours of NO2 are formed which turn the nitric acid yellowish in colour.
(iv) A white precipitate of silver chloride is formed which is soluble in excess of ammonium hydroxide.
(v) Blue coloured crystals of hydrated copper sulphate crumble down to form white anhydrous copper sulphate powder.
(i) Solid sodium chloride does not conduct electricity because the oppositely charged ions in sodium chloride are held together by strong electrostatic force of attraction and hence, they are not free.
(ii) The combining elements in hydrogen molecule are identical. They have no difference in their electronegativities. Hence, the shared pair of electrons lies exactly in the centre of two combining atoms. Therefore, the bond formed is non-polar covalent bond.
(iii) The reaction mixture should not be heated beyond 200°C because nitric acid decomposes at high temperature to give nitrogen dioxide. Above 200°C sodium sulphate forms hard crust which sticks to the walls of apparatus and is difficult to remove due to which apparatus is damaged.
4HNO3 → 4NO2 + 2H2O + O2
(iv) Noble gases have zero electron affinity because their outermost shell is complete and they have stable electronic configuration. Therefore, they cannot accept electrons.
(v) Ionisation potential increases as we move across a period because the atomic size decreases.
(v) Tollen’s reagent
(i) According to Avogadro’s law, under the similar conditions of temperature and pressure, equal volumes of all gases contain equal number of molecules.
The two applications of Avogadro’s law are:
I. It is used to determine the molecular formula of a gas.
II. It is used to determine the relation between molecular mass and vapour density.
(i) (A) Hg
(ii) (A) physical change.
(iii) (A) Group 17.
(iv) (B) amphoteric oxide.
(v) (C) three covalent bonds and one lone pair of
(vi) (A) reddish brown gas.
(vii) (D) Vanadium pentoxide.
(viii) (C) SO2 and CO2.
(ix) (A) position isomers.
(x) (B) carboxylic acid.
(i) Cu + 2H2SO4 (conc.) → CuSO4 + 2H2O + SO2
(ii) CaC2 + 2H2O → Ca(OH)2 + C2H2
(iii) 2H2S + SO2 → 2H2O + 3S
(iv) Pb(NO3)2 + H2SO4(dil.) PbSO4 + 2HNO3
(v) 3CuO + 2NH3 3Cu + N2 + 3H2O