{"id":14811,"date":"2024-02-06T10:35:34","date_gmt":"2024-02-06T05:05:34","guid":{"rendered":"https:\/\/wordpress-505192-1602719.cloudwaysapps.com\/?p=14811"},"modified":"2024-02-06T17:21:39","modified_gmt":"2024-02-06T11:51:39","slug":"tamil-nadu-11th-chemistry-model-question-paper-4-english-medium","status":"publish","type":"post","link":"https:\/\/samacheerguru.com\/tamil-nadu-11th-chemistry-model-question-paper-4-english-medium\/","title":{"rendered":"Tamil Nadu 11th Chemistry Model Question Paper 4 English Medium"},"content":{"rendered":"

Students can Download Tamil Nadu 11th Chemistry Model Question Paper 4 English Medium Pdf, Tamil Nadu 11th Chemistry Model Question Papers<\/a> helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.<\/p>\n

TN State Board 11th Chemistry Model Question Paper 4 English Medium<\/h2>\n

\"Tamil<\/p>\n

Time: 2\u00bd Hours
\nTotal Score: 70 Marks<\/p>\n

General Instructions:<\/span><\/p>\n

    \n
  1. The question paper comprises of four<\/span> parts.<\/li>\n
  2. You are to attempt all the parts. An internal choice of questions is provided wherever applicable.<\/li>\n
  3. All questions of Part I. II, III and IV are to be attempted separately.<\/li>\n
  4. Question numbers 1<\/span> to 15<\/span> in Part I<\/span> are Multiple Choice Questions of one mark each. These are to be answered by choosing the most suitable answer from the given four alternatives and writing the option code and the corresponding answer.<\/li>\n
  5. Question numbers 16<\/span> to 24<\/span> in Part II<\/span> are two-mark questions. These are to be answered in about one or two sentences.<\/li>\n
  6. Question numbers 25<\/span> to 33<\/span> in Part III<\/span> are three-mark questions. These are to be answered in about three to five short sentences.<\/li>\n
  7. Question numbers 34<\/span> to 38<\/span> in Part IV<\/span> are five-mark questions. These are to be answered in detail. Draw diagrams wherever necessary.<\/li>\n<\/ol>\n

    \"Tamil<\/p>\n

    PART -1<\/span><\/p>\n

    Answer all the questions. [15 x 1 = 15]<\/span>
    \nChoose the most suitable answer from the given four alternatives.<\/span><\/p>\n

    Question 1.
    \nCarbon forms two oxides, namely carbon monoxide and carbon dioxide. The equivalent mass of which element remains constant?
    \n(a) Carbon
    \n(b) Oxygen
    \n(c) Both carbon and oxygen
    \n(d) Neither carbon nor oxygen
    \nAnswer:
    \n(b) Oxygen<\/p>\n

    Reaction 1 : 2 C + O2<\/sub> \u2192 2 CO
    \n2 x 12 g carbon combines with 32 g ofoxygen.
    \nHence, Equivalent mass of carbon = \\(\\frac{2 \\times 12}{32}\\) x 8 = 6<\/p>\n

    Reaction 2 : C + O2<\/sub> \u2192 CO2<\/sub>
    \n12 g carbon combines with 32 g of oxygen.
    \nHence, Equivalent mass of carbon = \\(\\frac{12}{32}\\) x 8 = 3<\/p>\n

    \"Tamil<\/p>\n

    Question 2.
    \nElectronic configuration of species M2+<\/sup> is Is2<\/sup> 2s2<\/sup> 2p6<\/sup> 3s2<\/sup> 3p6<\/sup> 3d6<\/sup> and its atomic weight is 56.
    \nThe number of neutrons in the nucleus of species M is ………………… .
    \n(i) 26
    \n(b) 22
    \n(c) 30
    \n(iv) 24
    \nAnswer:
    \n(c) 30<\/p>\n

    Solution:
    \nM2+<\/sup> : 1s2<\/sup> 2s2<\/sup> 2p6<\/sup> 3s2<\/sup> 3p6<\/sup> 3d6<\/sup> ; M : Is2<\/sup> 2s2<\/sup> 2p6<\/sup> 3s2<\/sup> 3p6<\/sup> 3d8<\/sup>
    \nAtomic number = 26
    \nMass number = 56
    \nNo. of neutrons = 56 – 26 = 30<\/p>\n

    Question 3.
    \nAssertion: Helium has the highest value of ionization energy among all the elements known Reason: Helium has the highest value of electron affinity among all the elements known
    \n(a) Both assertion and reason are true and reason is correct explanation for the assertion
    \n(b) Both assertion and reason are true but the reason is not the correct explanation for the assertion
    \n(c) Assertion is true and the reason is false
    \n(d) Both assertion and the reason are false
    \nAnswer:
    \n(c) Assertion is true and the reason is false<\/p>\n

    \"Tamil<\/p>\n

    Question 4.
    \nAt room temperature normal hydrogen consists of
    \n(a) 25% ortho form + 75% para form
    \n(b) 50% ortho form + 50% para form
    \n(c) 75% ortho form + 25% para form
    \n(d) 60% ortho form + 40% para form
    \nAnswer:
    \n(c) 75% ortho form + 25% para form<\/p>\n

    Question 5.
    \nMatch the following.
    \nList-I List-II
    \nA. Beryllium – 1. Sacrificial anode
    \nB. Calcium – 2. X-ray tube radiation window
    \nC. Magnesium – 3. Scavenger to remove oxygen in TV
    \nD. Barium – 4. Getter in vacuum tubes
    \nCode: A B C D
    \n(a) 4 2 3 1
    \n(b) 2 4 1 3
    \n(c) 3 1 4 .2
    \n(d) 1 3 2 4
    \nAnswer:
    \n(b) 2 4 1 3<\/p>\n

    \"Tamil<\/p>\n

    Question 6.
    \nWhich of the following pair will diffuse at the same rate?
    \n(a) CO2<\/sub> and N2<\/sub>O
    \n(b) CO2<\/sub> and NO
    \n(c) CO2<\/sub> and CO
    \n(d) N2<\/sub>O and NO
    \nAnswer:
    \n(a) CO2<\/sub> and N2<\/sub>O<\/p>\n

    Question 7.
    \nAn ideal gas expands from the volume of 1 x 10-3<\/sup> m3<\/sup> to 1 x 10-2<\/sup> m3<\/sup> at 300K against a constant pressure at 1 x 103<\/sup> Nm-2<\/sup>. The work done is ………………… .
    \n(a) -900 J
    \n(b) 900 kJ
    \n(c) 270 kJ
    \n(d) -900 kJ
    \nAnswer:
    \n(a) -900 J<\/p>\n

    w = P\u0394V
    \nw = – (1 x 105 Nm-2<\/sup>) (1 x 10-2<\/sup> m3<\/sup> – 1 x 10-3<\/sup> m3<\/sup>)
    \nw = 105 <\/sup>(10-2<\/sup> – 10-3<\/sup>) Nm
    \nw = 105<\/sup>(10 – 1) 10-3<\/sup>) J
    \nw = 105<\/sup> (9 x 10-3<\/sup>) J
    \nw = 9 x 102<\/sup> J
    \nw = -900 J<\/p>\n

    \"Tamil<\/p>\n

    Question 8.
    \nAt a given temperature and pressure, the equilibrium constant values for the equilibria
    \n\"Tamil
    \nThe reaction between K1<\/sub> and K2<\/sub> is …………………. .
    \n\"Tamil
    \nAnswer:
    \nb<\/p>\n

    Solution:
    \n\"Tamil<\/p>\n

    \"Tamil<\/p>\n

    Question 9.
    \nConsider the following statements.
    \n(i) Henry\u2019s law is applicable at moderate temperature and pressure only.
    \n(ii) Highly soluble gases obey\u2019s Henry\u2019s law.
    \n(iii) The gases react with the solvent do not obey Henry\u2019s law.
    \nWhich of the above statements is\/are not correct?
    \n(a) (i) only
    \n(b) (ii) only
    \n(c) (iii) only
    \n(d) (i) and (ii)
    \nAnswer:
    \n(b) (ii) only<\/p>\n

    Question 10.
    \nWhich one of the following is the likely bond angles of sulphur tetrafluoride molecule?
    \n(a) 120\u00b0, 80\u00b0
    \n(b) 109\u00b0.28
    \n(c) 90\u00b0
    \n(d) 89\u00b0, 117\u00b0
    \nAnswer:
    \n(d) 89\u00b0, 117\u00b0<\/p>\n

    \"Tamil<\/p>\n

    \"Tamil<\/p>\n

    Solution:
    \nNormal bond angle in regular trigonal bipyramidal are 90\u00b0 and 120\u00b0. Due to l.p – b.p repulsion, bond angle is reduced to 89\u00b0, 117\u00b0 option (d).<\/p>\n

    Question 11.
    \nThe method used to estimate nitrogen in foods and fertilisers is
    \n(a) Dumas method
    \n(b) Kjeldahl\u2019s method
    \n(c) Carius method
    \n(d) Oxide method
    \nAnswer:
    \n(b) Kjeldahl\u2019s method<\/p>\n

    Question 12.
    \nWhich of the following carbocation will be most stable?
    \n\"Tamil
    \nAnswer:
    \nd<\/p>\n

    \"Tamil<\/p>\n

    Question 13.
    \nWhich one of the following is used as a soil sterilizing agent?
    \n\"Tamil
    \nAnswer:
    \n\"Tamil<\/p>\n

    Question 14.
    \nWhich of the following pair of oxides is responsible for acid rain?
    \n(a) Chloroform
    \n(b) Chloral
    \n(c) Iodoform
    \n(d) Chloropicrin
    \nAnswer:
    \n(d) Chloropicrin<\/p>\n

    Question 15.
    \nWhich of the following pair of oxides is responsible for acid rain?
    \n(a) SO3<\/sub> + NO2<\/sub>
    \n(b) CO2<\/sub> + CO
    \n(c) N2<\/sub>O + CH4<\/sub>
    \n(d) O2 <\/sub>+ H2<\/sub>
    \nAnswer:
    \n(a) SO3<\/sub> + NO2<\/sub><\/p>\n

    \"Tamil<\/p>\n

    PART- II<\/span><\/p>\n

    Answer any six questions.in which question No. 20 is compulsory.<\/span><\/p>\n

    Question 16.
    \nCalculate the number of moles present in 9g of ethane?
    \nAnswer:
    \nMass of ethane = 9 g
    \nMolar mass of ethane C2<\/sub>H6<\/sub> = 30 g mol-1<\/sup>.
    \n\\(\\text { No. of moles }=\\frac{\\text { Mass }}{\\text { Molar mass }}=\\frac{9}{30}=0.3 \\mathrm{mol}\\)<\/p>\n

    Question 17.
    \nWhy did halogens act as oxidizing agents?
    \nAnswer:
    \nHalogens act as oxidizing agents. Their electronic configuration is ns2 np5. So all the halogens are ready to gain one electron to attain the nearest inert gas configuration. An oxidizing agent is the one which is ready to gain an electron. So all the halogens act as oxidizing agents. Also halogens are highly electronegative with low dissociation energy and high negative electron gain enthalpies. Therefore, the halogens have a high tendency to gain an electron. Hence they act as oxidizing agents.<\/p>\n

    \"Tamil<\/p>\n

    Question 18.
    \nWould it be easier to drink water with a straw on the top of Mount Everest?
    \nAnswer:
    \nIt is difficult to drink water with a straw on the top of Mount Everest. This is because the reduced atmospheric pressure is less effective in pushing water into the straw at the top of the mountain because gravity falls off gradually with height. The air pressure falls off, there isn\u2019t enough atmospheric pressure to push the water up in the straw all the way to the mouth.<\/p>\n

    Question 19.
    \nBe(OH)2<\/sub>\u00a0is amphoteric in nature. Prove it.
    \nAnswer:
    \nBe(OH)2<\/sub> is amphoteric in nature as it reacts with both acid and alkali.<\/p>\n

      \n
    • Be(OH)2<\/sub> + 2NaOH \u2192 Na2<\/sub>BeO2<\/sub> + 2H2<\/sub>O
      \n(Acidic)<\/li>\n
    • Be(OH)2<\/sub> + 2HC1 \u2192 BeCl2<\/sub>\u00a0+ 2H2<\/sub>O
      \n(Basic)<\/li>\n<\/ul>\n

      Question 20.
      \nAn engine operating between 127\u00b0C and 47\u00b0C takes some specified amount of heat from a high temperature reservoir. Calculate the percentage efficiency of an engine.
      \nAnswer:
      \nGiven: T1<\/sub> = 127\u00b0C = 127 + 273 = 400K
      \nT2<\/sub> = 47\u00b0C = 47 + 273 = 320 K
      \n% efficiency q?
      \n\"Tamil<\/p>\n

      \"Tamil<\/p>\n

      Question 21.
      \nCalculate the formal charge on each atom of carbonyl chloride (COCl2<\/sub>)?
      \nAnswer:
      \n\"Tamil<\/p>\n

      Question 22.
      \nWhy we need to purify the organic compounds?
      \nAnswer:
      \nIn order to study the structure, physical properties, chemical properties and biological properties of organic compounds, they must be in the pure state. So organic compounds must be purified.<\/p>\n

      \"Tamil<\/p>\n

      Question 23.
      \nWhat are electrophiles? Give an example.
      \nAnswer:
      \nElectrophiles: Electrophiles are reagents that are attracted towards negative charge or electron rich center. They are either positively charged ions or electron deficient neutral molecules.<\/p>\n

      Example:
      \nCO2<\/sub>, A1Cl3<\/sub>, BF3<\/sub>, FeCl3<\/sub>, NO+<\/sup>, NO2+<\/sup><\/sub>, etc.<\/p>\n

      Question 24.
      \nComplete the reaction, C2<\/sub>H5<\/sub>NH2
      \n<\/sub>\"Tamil
      \nAnswer:
      \n\"Tamil<\/p>\n

      Part – III<\/span><\/p>\n

      Answer any six questions in which question No. 30 is compulsory. [6 x 3 = 18]<\/span><\/p>\n

      Question 25.
      \nOn the formation of SF6<\/sub> by the direct combination of S and F2<\/sub>, which is the limiting reagent? Prove it.
      \nAnswer:
      \nSF6<\/sub> is formed by burning Sulphur in an atmosphere of Fluorine. Suppose 3 moles of S is allowed to react with 12 moles of Fluorine.
      \n\\(\\mathrm{S}_{(\\mathrm{o}}+3 \\mathrm{F}_{2_{(\\mathrm{g})}} \\rightarrow \\mathrm{SF}_{6(\\mathrm{g})}\\)<\/p>\n

      \"Tamil<\/p>\n

      As per the stoichiometric reaction, one mole of S reacts with 3 moles of fluorine to complete the reaction. Similarly, 3 moles of S requires only 9 moles of fluorine.<\/p>\n

      \u2234 It is understood that the limiting reagent is Sulphur and the excess reagent is Fluorine.<\/p>\n

      Question 26.
      \nExplain about the significance of de-Broglie equation.
      \nAnswer:<\/p>\n

        \n
      • \\(\\lambda=\\frac{h}{m v}\\) This equation implies that a moving particle can be considered as a wave and a wave
        \ncan exhibit the properties of a particle.<\/li>\n
      • For a particle with high linear momentum (mv) the wavelength will be so small and cannot be observed.<\/li>\n
      • For a microscopic particle such as an electron, the mass is of the order of 10 31 kg, hence the wavelength is much larger than the size of atom and it becomes significant.<\/li>\n
      • For the electron, the de Broglie wavelength is significant and measurable while for the iron ball it is too small to measure, hence it becomes insignificant.<\/li>\n<\/ul>\n

        Question 27.
        \nWhat are all the factors that influences electron affinity?
        \nAnswer:
        \nFactors that affects electron affinities are size of the atom, effective nuclear charge, screening effect.<\/p>\n

          \n
        • \\(Electron affinity \\propto \\frac{1}{\\text { Size of the atom }}\\)<\/li>\n
        • Electron affinity QC Effective nuclear charge<\/li>\n
        • \\(Electron affinity \\propto \\frac{1}{\\text { Screening effect }}\\)<\/li>\n<\/ul>\n

          \"Tamil<\/p>\n

          Question 28.
          \nDescribe about the biological importance of sodium and potassium.
          \nAnswer:<\/p>\n

            \n
          • Monovalent sodium and potassium ions are found in large proportions in biological fluids.<\/li>\n
          • These ions perform important biological functions such as maintenance of ion balance and nerve impulse conduction.<\/li>\n
          • Sodium – Potassium play an important role in transmitting nerve signals.<\/li>\n
          • A typical 70 kg man has 90 g of Na and 170 g of K.<\/li>\n
          • Sodium ions are found on the outside of cells, being located in blood plasma and in the interstitial fluid which surrounds the cells. These ions participate in the transmission of nerve signals, in regulating the flow of water across cell membranes and in the transport of sugars and amino acids into cells.<\/li>\n
          • Potassium ions are the most abundant cations within cell fluids, where they activate many enzymes, participate in the oxidation of glucose to produce ATP and with sodium, are responsible for the transmission of nerve signals.<\/li>\n<\/ul>\n

            Question 29.
            \nWhat are the conventions adopted in writing the thermochemical equation?
            \nAnswer:
            \nA thermochemical equation is a balanced stoichiometric chemical equation that includes the enthalpy change (\u0394H).<\/p>\n

            Conventions adopted in thermochemical equations:<\/p>\n

              \n
            • The coefficients in a balanced thermochemical equation refer to number of moles of reactants and products involved in the reaction.<\/li>\n
            • The enthalpy change of the reaction \u0394H has unit kJ.<\/li>\n
            • When the chemical reaction is reversed, the value of \u0394H is reversed in sign with the same magnitude.<\/li>\n
            • Physical states (gas, liquid, aqueous and solid) of all species is important and must be specified in a thermochemical reaction since \u0394H depends on the phases of reactants and products.<\/li>\n
            • If the thermochemical equation is multiplied throughout by a number, the enthalpy change is also be multiplied by the same number value.<\/li>\n
            • The negative sign of \\(\\Delta \\mathrm{H}_{r}^{o}\\) indicates the reaction to be an exothermic and the positive sign of \\(\\Delta \\mathrm{H}_{r}^{o}\\) indicates an endothermic type of reaction.<\/li>\n<\/ul>\n

              \"Tamil<\/p>\n

              Question 30.
              \nCalculate the work done when 2-moles of an ideal gas expands reversibly and isothermally from a volume of 500 mL to a volume 2 L at 25\u00b0C and normal pressure.
              \nAnswer:
              \nGiven
              \n\"Tamil<\/p>\n

              Question 31.
              \nFor a gaseous homogeneous reaction at equilibrium number of moles of products are greater than the number of moles of reactants. Is K is larger or smaller than Kr<\/sub>.
              \nAnswer:
              \nFor a homogeneous reaction at equilibrium, number of moles of products (np<\/sub>) are greater than the number of moles of reactants (nR<\/sub>), then \u0394ng<\/sub> = +ve
              \n\"Tamil<\/p>\n

              Question 32.
              \nExplain – Resonance.
              \nAnswer:
              \n(i) Certain organic compounds can be represented by more than one structure and they differ only in the position of bonding and lone pair of electrons. Such structures are called resonance structure and this phenomenon is called as resonance.<\/p>\n

              \"Tamil<\/p>\n

              This phenomenon is also called as mesomerism or mesomeric effect.
              \n(ii) For example, the structure of aromatic compounds such as benzene and conjugated system like 1,3 butadiene cannot be represent by a single structure and their observed properties can be explained on the base of a resonance hybrid.
              \n(iii) Resonance structure of benzene.
              \n\"Tamil
              \n(I) and (II) are called, as resonance hybrids of benzene.
              \n(iv) For 1,3 butadiene:
              \n\"Tamil<\/p>\n

              (I), (II) and (III) are called as resonance hybrids of 1,3 butadiene.<\/p>\n

              Question 33.
              \nToluene undergoes nitration easily than benzene. Why?
              \nAnswer:<\/p>\n

                \n
              • Toluene has a methyl group on the benzene ring which is electron releasing group and hence activate the benzene ring by pushing the electrons on the benzene ring.<\/li>\n
              • CH3<\/sub> group is ortho – para director and ring activator. Therefore in toluene, ortho and para positions are the most reactive towards an electrophile, thus promoting electrophilic substitution reaction.<\/li>\n
              • The methyl group hence makes it around 25 times more reactive than benzene. Therefore it undergoes nitration easily than benzene.
                \n\"Tamil<\/li>\n<\/ul>\n

                \"Tamil<\/p>\n

                Part – IV<\/span><\/p>\n

                Answer all the questions. [5 x 5 = 25]<\/span><\/p>\n

                Question 34.
                \n(a) (i) Explain about the classification of matter. (3)
                \n(ii) What is a combination reaction? Give an example. (2)
                \n[OR]
                \n(b) (i) Define – electronegativity. (2)
                \n(ii) How Moseley determined the atomic number of an element using X-rays. (3)
                \nAnswer:
                \n(a) (i) Classification of matter:
                \n\"Tamil
                \n(ii) When two or more substances combine to form a single substance, the reactions are called combination reactions.
                \nA + B \u2192 C
                \nExample: 2 Mg + O2<\/sub> \u2192 2MgO
                \n[OR]
                \n(b) (i) Electronegativity is the relative tendency of an element present in a covalently bonded molecule, to attract the shared pair of electrons towards itself.<\/p>\n

                \"Tamil<\/p>\n

                (ii)<\/p>\n

                  \n
                • Henry Moseley studied the X-ray spectra of several elements and determined their atomic numbers (Z).<\/li>\n
                • He discovered a correlation between atomic number and the frequency of X-rays generated by bombarding an element with high energy of electrons.<\/li>\n
                • Moseley correlated the frequency of the X-ray emitted by an equation as, \\(\\sqrt{\\mathfrak{v}}=a(\\mathrm{Z}-b)\\)
                  \nWhere u = Frequency of the X-rays emitted by the elements. a and. b = Constants.<\/li>\n
                • From the square root of the measured frequency of the X-rays emitted, he determined the atomic number of the element.<\/li>\n<\/ul>\n

                  Question 35.
                  \n(a) Explain the following observations,
                  \n(i) Aerated water bottles are kept under water during summer. (3)
                  \n(ii) Liquid ammonia bottle is cooled before opening the seal. (2)
                  \n[OR]
                  \n(b) Derive the relation between \u0394H and \u0394U for an ideal gas. (5)
                  \nAnswer:
                  \n(a) (i) In aerated water bottles, CO2<\/sub> gas is passed through the aqueous solution under pressure because the solubility of the gas in water is not very high. In summer, the solubility of the gas in water is likely to decrease because of the rise in temperature. Thus, in summer, more \u2019 of gas will be present above the liquid surface in the glass bottle. In case, the pressure of the gas becomes too high, the glass will not be able to withstand the pressure and the bottle may explode. To avoid this, the bottles are kept under water. As a result, the temperature is likely to decrease and the solubility of CO2<\/sub> is likely to increase in aqueous solution resulting in decreased pressure.<\/p>\n

                  \"Tamil<\/p>\n

                  (ii) Liquid ammonia bottle contains the gas under very high pressure. If the bottle is opened as such, then the sudden decrease in pressure will lead to a large increase in volume of the gas. As a result, the gas will come out of the bottle all of a sudden with force. This will lead to the breakage of the bottle and also causes accident However, if the bottle is cooled under tap water for sometime, there will be a decrease in the volume of a gas to a large extent. If the seal is opened now, the gas will come out of the bottle at a slower rate, reduces the chances of accident.
                  \n[OR]
                  \n(b) Relation between \u0394H and \u0394U for an ideal gas.
                  \n1. When the system at constant pressure undergoes changes from an initial state with Hp U1<\/sub>, V1<\/sub> and P parameters to a final state with H2<\/sub>, U2<\/sub>, V2<\/sub> and P parameters, the change in enthalpy AH, is given by
                  \n\u2206H = U + PV
                  \n2. At initial state H1<\/sub> = U1<\/sub> + PV1<\/sub>\u00a0……………….. (1)
                  \nAt final state H2<\/sub> = U2<\/sub> + PV2<\/sub> ……………….. (2)
                  \n(2) – (1) \u21d2 (H2<\/sub> – H1<\/sub>) = (U2<\/sub> – U1<\/sub>) + P (V2<\/sub> – V1<\/sub>)
                  \n\u2206H = \u2206U + P\u2206V …………………… (3)
                  \nConsidering \u2206U = q + w ; w = – P\u2206V
                  \n\u2206H = q + w + PAV
                  \n\u2206H = qp<\/sub> – PAV+ PAV
                  \n\u2206H = qp<\/sub> ………………… (4)<\/p>\n

                  \"Tamil<\/p>\n

                  qp<\/sub> is the heat absorbed at constant pressure and is considered as heat content.<\/p>\n

                  3. Consider a closed system of gases which are chemically reacting to produce product gases at constant temperature and pressure with V. and Vf as the total volumes of the reactant and product gases respectively, and n. and nf are the number of moles of gaseous reactants and products. Then,
                  \nFor reactants: PVi<\/sub> = ni<\/sub>RT
                  \nFor products : P Vf<\/sub><\/em> = nf<\/sub><\/em> RT<\/p>\n

                  Then considering reactants as initial state and products as final state,
                  \nP (Vf<\/sub><\/em> – Vi<\/sub>) = (nf<\/sub><\/em> – ni<\/sub>) RT
                  \nP\u2206V = \u2206ng<\/sub> RT<\/p>\n

                  We know
                  \n\u2206H = \u2206U + P\u2206V
                  \n\u2206H = \u2206U + \u2206ng<\/sub> RT …………………. (5)<\/p>\n

                  Question 36.
                  \n(a) (i) What are heterogenous equilibrium? Give an example. (2)
                  \n(ii) The atmospheric oxidation of NO 2NO(g)<\/sub> + O2(g)<\/sub> = 2NO2(g)<\/sub> was studied with initial pressure of 1-atm of NO and 1-atm of O2<\/sub>. At equilibrium partial pressure of oxygen is 0.52 atm. Calculate Kp<\/sub> of the reaction. (3)
                  \n[OR]
                  \n(b) (i) Explain the factors influencing the solubility of the solutes. (3)
                  \n(ii) Why the carbonated drinks are stored in a pressurised container? (2)
                  \nAnswer:
                  \n(a) (i) Heterogeneous equilibrium: If the reactants and products of a reaction in equilibrium are in different phases, then it is called as heterogeneous equilibrium.
                  \n\"Tamil<\/p>\n

                  \"Tamil<\/p>\n

                  (b) (i) Factors influencing solubility:
                  \nNature of solute and solvent: Sodium chloride, an ionic compound readily dissolves in , polar solvent such as water but it does not dissolve in non polar solvent such as benzene. Most of the organic compounds dissolve in organic solvent and do not dissolve in water.<\/p>\n

                  Effect of temperature: Generally, the solubility of a solid solute in a liquid solvent increases with increase in temperature. The dissolution of NaCl does not vary as the maximum solubility is achieved at normal temperature. The dissolution of ammonium nitrate is endothermic, the solubility increases with increase in temperature. The dissolution of ceric sulphate is exothermic and the solubility decreases with increase of temperature. In the case of gaseous solute in liquid solvent the solubility decreases with increase in temperature.<\/p>\n

                  Effect of pressure: Generally the change in pressure does not have any significant effect in the solubility of solids and liquids as they are not compressible. However, the solubility of gases generally increases with increase of pressure.<\/p>\n

                  (ii)<\/p>\n

                    \n
                  • The carbonated beverages contain CO2<\/sub> dissolved in them. To dissolve the CO2<\/sub> in these drinks, CO2<\/sub> gas is bubbled through them under high pressure.<\/li>\n
                  • These containers are sealed to maintain the pressure. When we open these containers at atmospheric pressure, the pressure of the CO2<\/sub> drops to the atmospheric pressure level and hence bubbles of CO2<\/sub> rapidly escape from the solution and show effervescence.<\/li>\n<\/ul>\n

                    \"Tamil<\/p>\n

                    Question 37.
                    \n(a) (i) Explain – paper chromatography. (3)
                    \n(ii) What are stereo-isomerism? (2)
                    \n[OR]
                    \n(b) (i) Explain the homolytic fission of a covalent bond? (3)
                    \n(ii) Why chloroacetic acid is more acidic than acetic acid? (2)
                    \nAnswer:
                    \n(a) (i) 1. It is an example of partition chromatography. A strip of paper acts as an adsorbent.
                    \nThis method involves continues differential pardoning of components of a mixture between stationary and mobile phase. In paper chromatography, a special quality paper known as chromatographic paper is used. This paper act as a stationary phase.
                    \n2. A strip of chromatographic paper spotted at the base with the solution of the mixture is suspended in a suitable solvent which acts as the mobile phase. The solvent rises up and flows over the spot. The paper selectivity retains different components according to their different partition in the two phases where a chromatogram is developed.
                    \n3. The spots of the separated coloured components are visible at different heights from the position of initial spots on the chromatogram. The spots of the separated colourless compounds may be observed either under ultraviolet light or by the use of an appropriate spray reagent.<\/p>\n

                    (ii) Stereo-isomerism: The isomers which have same bond connectivity but different arrangement of groups or atoms in space are known as stereoisomers. This phenomenon is known as stereoisomerism.<\/p>\n

                    [OR]<\/p>\n

                    \"Tamil<\/p>\n

                    (b) (i)<\/p>\n

                      \n
                    • Homolytic cleavage is the process in which a covalent bond breaks symmetrically in such way that fcach of the bonded atoms retains one electron.<\/li>\n
                    • This type of cleavage occurs under high temperature or in the presence of UV light.<\/li>\n
                    • In a compound containing non-‘polar covalent bond formed between atoms of similar electronegativity, in such molecules the cleavage of bonds results into free radicals.<\/li>\n
                    • For example, ethane undergo homolytic fission to produce, two methyl free radicals.
                      \n\"Tamil<\/li>\n<\/ul>\n

                      (ii) Chloro acetic acid:
                      \n\"Tamil
                      \nChloro acetic acid has Cl-group and it has high electronegativity and shows -I effect. Therefore Cl-atom to facilitate the dissociation of O-H bond very fastly. Whereas in the – case of acetic acid, has CH3<\/sub> group and it shows +1 effect, therefore dissociation of O-H bond will be more difficult. Thus chloro acetic acid is stronger acid than acetic acid.<\/p>\n

                      \"Tamil<\/p>\n

                      Question 38.
                      \n(a) \"Tamil
                      \nIdentify A and B (major products).
                      \n(ii) Describe the mechanism of sulphonation of benzene. (3)
                      \n[OR]
                      \n(b) An organic compounds A of a molecular formula C6<\/sub>H6<\/sub> which is simple aromatic hydrocarbon. A reacts with Cl2<\/sub> in presence of FeCl3<\/sub> to give B. B reacts with NaOH at 350\u00b0C and 300 atm pressure to give C. B again reacts with ammonia at 250\u00b0C and 50 atm pressure to give D. Identify A, B, C and D explain the reaction. (5)
                      \nAnswer:
                      \n\"Tamil
                      \n(ii) Step 1: Generation of SO3 electrophile: 2H2<\/sub>SO4<\/sub> \u2192 H3<\/sub>O + SO3<\/sub> + HSO4<\/sub>
                      \nStep 2: Attack of the electrophilic on benzene ring to form Armenian ion:
                      \n\"Tamil
                      \n\"Tamil<\/p>\n

                      \"Tamil<\/p>\n\n\n\n\n\n\n
                      A<\/td>\nC6<\/sub>H6<\/sub><\/td>\nBenzene<\/td>\n<\/tr>\n
                      B<\/td>\nC6<\/sub>H5<\/sub>Cl<\/td>\nChlorobenzene<\/td>\n<\/tr>\n
                      C<\/td>\nC6<\/sub>H5<\/sub>OH<\/td>\nPhenol<\/td>\n<\/tr>\n
                      D<\/td>\nC6<\/sub>H5<\/sub>NH2<\/sub><\/td>\nAniline<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"excerpt":{"rendered":"

                      Students can Download Tamil Nadu 11th Chemistry Model Question Paper 4 English Medium Pdf, Tamil Nadu 11th Chemistry Model Question Papers helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations. TN State Board 11th Chemistry Model Question Paper 4 English Medium Time: 2\u00bd Hours Total Score: […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":"","footnotes":""},"categories":[7],"tags":[],"blocksy_meta":"","jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/posts\/14811"}],"collection":[{"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/comments?post=14811"}],"version-history":[{"count":1,"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/posts\/14811\/revisions"}],"predecessor-version":[{"id":55651,"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/posts\/14811\/revisions\/55651"}],"wp:attachment":[{"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/media?parent=14811"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/categories?post=14811"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/samacheerguru.com\/wp-json\/wp\/v2\/tags?post=14811"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}