ICSE BOARD PAPER-2014-X-Chemistry 2014 Set-1 2014 Set 1

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  • Q1

    (a) State the conditions required for the following reactions to take place:

    (i) Catalytic hydrogenation of ethyne.

    (ii) Preparation of ethyne from ethylene dibromide.

    (iii) Catalytic oxidation of ammonia to nitric oxide.

    (iv) Any two conditions for the conversion of sulphur dioxide to sulphur trioxide.

    (b) State the main components of the following alloys:

    (i) Brass.

    (ii) Duralumin.

    (iii) Bronze.

    (c) Give balanced equations for the following:

    (i) Laboratory preparation of nitric acid.

    (ii) Preparation of ethanol from monochloroethane and aq. sodium hydroxide.
    [5+3+2 = 10]

    Marks:10
    Answer:

    (i) Ethyne adds to hydrogen in the presence of a catalyst like Ni or Pt on heating upto 473 K to form ethene, which undergoes further addition to form ethane.

    (ii) Ethylene dibromide reacts with hot alcoholic KOH solution.

    (iii) In presence of platinum at 800C in presence of oxygen atmospheric pressure.

    (iv) In presence of vanadium pentaoxide at 450C and 2 atmospheric pressure.

    (b)(i) Copper and Zinc

    (ii) Aluminium and magnesium

    (iii) Copper and Tin

    (c) (i) Laboratory Preparation of Nitric acid

    (ii) Preparation of ethanol from monochloroethane and aq. sodium hydroxide

    View Answer
  • Q2

    (a) Give the structural formula of the following:

    (i) Ethanol.

    (ii) 1-Propanal.

    (iii) Ethanoic acid.

    (iv) 1, 2- Dichloroethane.

    (b) Draw the structure of the stable positive ion formed when an acid dissolves in water.

    (c) State the inference drawn from the following observations:

    (i) On carrying out the flame test with a salt P a brick red flame was obtained. What is the cation in P?

    (ii) A gas Q turns moist lead acetate paper silvery black. Identify the gas Q.

    (iii) pH of liquid R is 10. What kind of substance is R?

    (iv) Salt S is prepared by reacting dilute sulphuric acid with copper oxide. Identify S.
    [4+2+4 = 10]

    Marks:10
    Answer:


    View Answer
  • Q3

    (a) (i) State Avogadro’s Law.

    (ii) A cylinder contains 68 g of ammonia gas at STP

    (1) What is the volume occupied by this gas?

    (2) How many moles of ammonia are present in the cylinder?

    (3) How many molecules of ammonia are present in the cylinder? [N-14, H-1]

    (b)(i) Why do covalent compounds exist as gases, liquids or soft solids?

    (ii) Which electrode: anode or cathode is the oxidising electrode? Why?

    (c) Name the kind of particles present in:

    (i) Sodium Hydroxide solution

    (ii) Carbonic acid

    (iii) Sugar solution [4+3+3 = 10]

    Marks:10
    Answer:

    (a) (i) Avogadro’s Law-Under the same conditions of temperature and pressure, equal volumes of all gases contain the same number of molecules.

    (ii)

    (b)(i)Covalent compounds are generally gases, liquids or soft solids due to the weak interatomic forces between the particles.

    (ii) Anode is an oxidising electrode. At the anode, the anion loses electrons to form neutral atoms.

    (c) (i) Sodium Hydroxide solution is a strong alkali, therefore, it contains sodium ions and hydroxide ions.

    (ii) Carbonic acid is a weak acid; therefore, it contains carbonate ions,hydronium ions and carbonic acid molecules.

    (iii) Sugar solution contains sugar molecules and water molecules.

    View Answer
  • Q4

    (a) An element Z has atomic number 16. Answer the following questions on Z

    (i) State the period and group to which Z belongs

    (ii) Is Z a metal or a non-metal?

    (iii) State the formula between Z and Hydrogen

    (iv) what kind of a compound is this?

    (b)M is a metal above hydrogen in the activity series and its oxide has the formula M2O. This oxide when dissolved in water forms the corresponding hydroxide, which is a good conductor of electricity. In the above context, answer the following:

    (i) What kind of combination exists between M and O?

    (ii) How many electrons are there in the outermost shell of M?

    (iii) Name the group to which M belongs.

    (iv) State the reaction taking place at the cathode.

    (v) Name the product at the anode.

    Marks:10
    Answer:

    (a) (i) Z belongs to 3rd period and group 16.

    (ii) Z is a non-metal.

    (iii) H2Z

    (iv) H2Z is a covalent compound.

    (b) (i) Electrovalent bond exists between M and O.

    (ii) 1 electron

    (iii) M belongs to first group.

    (iv)

    (v) Oxygen gas is liberated at anode.

    View Answer
  • Q5

    (a) Name the following:

    (i) The property possessed by metals by which they can be beaten into sheets.

    (ii) A compound added to lower the fusion temperature of electrolytic bath in the extraction of aluminum.

    (iii) The ore of zinc containing its sulphide.

    (b) Give one equation each to show the following properties of sulphuric acid:

    (i) Dehydrating property

    (ii) Acidic nature

    (iii) As a non-volatile acid

    (c) Give balanced chemical equations to prepare the following salts:

    (i) Lead sulphate from lead carbonate

    (ii) Sodium sulphate using dilute sulphuric acid

    (iii) Copper chloride using copper carbonate [3+3+4 = 10]

    Marks:10
    Answer:


    View Answer
  • Q6

    (a) State your observation in each of the following cases:

     

    (i) When dilute hydrochloric acid is added to sodium carbonate crystals.

    (ii) When excess sodium hydroxide is added to calcium nitrate solution.

    (iii) At the cathode when acidified aqueous copper sulphate solution is electrolysed with copper electrodes.

    (iv) When calcium hydroxide is heated with ammonium chloride crystals.

    (v) When moist starch iodide paper is introduced into chlorine gas.


    (b) Study the figure given below and answer the questions that follow:

     

    (i) Identify the gas Y.

    (ii) What property of gas Y does this experiment demonstrate?

    (iii) Name another gas, which has the same property and can be demonstrated through this experiment.


    (c) (i) Name the other ion formed when ammonia dissolves in water.

    (ii) Give one test that can be used to detect the presence of the ion produced.

    Marks:10
    Answer:

    (i) Brisk effervescences of colourless and odourless gas (carbon dioxide) is observed.

     

     

    (ii) White precipitate of calcium hydroxide is formed.

     

    (iii) Cathode becomes thick due to the deposition of red copper metal.

    (iv) A colourless gas with pungent smell (ammonia) is evolved.

    (v) When moist starch iodide paper is introduced into chlorine gas, it turns moist starch iodide paper blue-black.

    (b)

    (i)The Y gas is Hydrogen chloride.

    (ii) To show that gas Y (hydrogen chloride) is highly soluble in water.

    (iii) Ammonia gas

    (c) (i) Ammonium ion and hydroxide ion.

    (ii) It will give dirty green precipitate with iron (II) sulphate solution.

    View Answer
  • Q7

    Question 1

    (a) Choose the correct answer from the options given below:

    (i) Ionisation potential increases over a period from left to right because the:

    (A) Atomic radius increases and nuclear charge increases

    (B) Atomic radius decreases and nuclear charge decreases

    (C) Atomic radius increases and nuclear charge decreases

    (D) Atomic radius decreases and nuclear charge increases

    (ii) A compound X consists of only molecules. Hence, X will have:

    (A) A crystalline hard structure

    (B) A low melting point and low boiling point

    (C) An ionic bond

    (D) A strong force of attraction between its molecules.

    (iii) When fused lead bromide is electrolysed we observe:

    (A) a silver grey deposit at anode and a reddish brown deposit at cathode

    (B) a silver grey deposit at cathode and a reddish brown deposit at anode

    (C) a silver grey deposit at cathode and reddish brown fumes at anode

    (D) silver grey fumes at anode and reddish brown fumes at cathode

    (iv) The main ore used for the extraction of iron is:

    (A) Haematite

    (B) Calamine

    (C) Bauxite

    (D) Cryolite

    (v) Heating an ore in a limited supply of air or in the absence of air at a temperature just below its melting point is known as:

    (A) smelting

    (B) ore dressing

    (C) calcination

    (D) bessemerisation

    (vi) If an element A belongs to period 3 and group II then it will have:

    (A) 3 shells and 2 valence electrons

    (B) 2 shells and 3 valence electrons

    (C) 3 shells and 3 valence electrons

    (D) 2 shells and 2 valence electrons

    (vii) The molecule containing a triple co-valent bond is:

    (A) ammonia

    (B) methane

    (C) water

    (D) nitrogen

    (viii) The electrolyte used for electroplating an article with silver is:

    (A) silver nitrate solution

    (B) silver cyanide solution

    (C) sodium argentocyanide solution

    (D) nickel sulphate solution

    (ix) Aluminium powder is used in thermite welding because,

    (A) it is a strong reducing agent.

    (B) it is a strong oxidising agent.

    (C) it is corrosion resistant.

    (D) it is a good conductor of heat.

    (x) The IUPAC name of acetylene is,

    (A) propane.

    (B) propyne.

    (C) ethene.

    (D) ethyne

    (b) Fill in the blanks from the choices given with in

    brackets:

    (i) The basicity of acetic acid is _______ (3, 1, 4)

    (ii) The compound formed when ethanol reacts with sodium is _______(sodium ethanoate, sodium ethoxide, sodium propanoate)

    (iii) Quicklime is not used to dry HCl gas because _______ (CaO is alkaline, CaO is acidic, CaO is neutral)

    (iv) Ammonia gas is collected by _______ (an upward displacement of air, a downward displacement of air)

    (v) Cold, dilute nitric acid reacts with copper to form _______ (Hydrogen, nitrogen dioxide, nitric oxide)

    (c) Give one word or phrase for the following:

    (i) The ratio of the mass of a certain volume of gas to the mass of an equal volume of hydrogen under the same conditions of temperature and pressure.

    (ii) Formation of ions from molecules

    (iii) Electrolytic deposition of a superior metal on a baser metal.

    (iv) Hydrocarbons containing a functional group.

    (v) The amount of energy released when an atom in the gaseous state accepts an electron to form an anion.

    (d) Match the options A to E with the statements to (i) to (v):

    (A) Alkynes (i) No. of molecules in 22.4

    dm3 of CO2 at STP

    (B) Alkane (ii) An element with

    electronic configuration 2,8,8,3

    (C) Iron (iii) CnH2n+2

    (D) 6.023 x 1023 (iv) CnH2n-2

    (E) Metal (v) The metal that forms two types of ions.

    (e) Write balanced equations for the following:

    (i) Action of heat on a mixture of copper and concentrated nitric acid.

    (ii) Action of warm water on magnesium nitride.

    (iii) Action of concentrated sulphuric acid on carbon.

    (iv) Action of dilute hydrochloric acid on sodium sulphide.

    (v) Preparation of ethane from sodium propionate.

    (f) Distinguish between the following pairs of compounds using the test given within brackets:

    (i) Iron (II) sulphate and iron (III) sulphate (using ammonium hydroxide)

    (ii) A lead salt and a zinc salt (using excess ammonium hydroxide)

    (iii) Sodium nitrate and sodium sulphite (using dilute sulphuric acid)

    (iv) Dilute sulphuric acid and dilute hydrochloric acid (using barium chloride solution)

    (v) Ethane and ethene (using alkaline potassium permanganate solution)

    (g)Oxygen oxidises ethyne to carbon dioxide and water as shown by the equation:

    What volume of ethyne gas at STP is required to produce 8.4 dm3 of carbon dioxide at STP [H=1, C=2, O=16]

    (ii) A compound made up of two elements X and Y has an empirical formula X2Y. If the atomic weight of X is 10 and that of Y is 5 and the compound has a vapour density 25, find its molecular formula. [10+5+5+5+5+5+5 = 40]

    Marks:40
    Answer:

    (a)
    (i) (D)
    Atomic radius decreases and nuclear charge increases.

    (ii) (B) A low melting point and low boiling point

    (iii) (C) a silvery grey deposit at cathode and reddish brown fumes at anode

    (iv) (A) Haematite

    (v) (C) Calcination

    (vi) (A) 3 shells and 2 valence electrons

    (vii) (D) Nitrogen

    (viii) (C) Sodium argentocyanide solution

    (ix) (A) It is a strong reducing agent.

    (x) (D) ethyne


    (b)

    (i) 1

    (ii) sodium ethoxide
    (iii) CaO is alkaline

    (iv) a downward displacement of air

    (v) nitric oxide

    (c)

    (i) Vapour density

    (ii) Ionisation
    (iii) Electroplating

    (iv) Carbonyl compounds

    (v) Electron affinity

    (d) A (iv), B (iii), C (v), D (i), E (ii)

    (e)

    (f)

    (i) With ammonium hydroxide, Iron (II) sulphate gives dirty green precipitate while iron (III) sulphate gives reddish brown precipitate.

    (ii) With excess of ammonium hydroxide, zinc salt gives gelatinous white precipitate which dissolves in ammonium hydroxide solution while lead salt gives white precipitate which insoluble in NH4OH.

    (iii) With dilute sulphuric acid, sodium nitrate does not react while sodium sulphite gives colourless gas with smell of burning sulphur is liberated.

    (iv) With barium chloride, dilute sulphuric acid gives thick white precipitate of barium sulphate which remains insoluble in nitric acid while dilute hydrochloric acid does not give this reaction.

    (v) Ethene gas decolourises the alkaline potassium manganate solution while ethane does not.

    (g)

    View Answer