{"id":8904,"date":"2019-11-27T14:31:38","date_gmt":"2019-11-27T09:01:38","guid":{"rendered":"https:\/\/kseebsolutions.guru\/?p=8904"},"modified":"2021-07-02T15:44:52","modified_gmt":"2021-07-02T10:14:52","slug":"1st-puc-chemistry-question-bank-chapter-4","status":"publish","type":"post","link":"https:\/\/kseebsolutions.guru\/1st-puc-chemistry-question-bank-chapter-4\/","title":{"rendered":"1st PUC Chemistry Question Bank Chapter 4 Chemical Bonding and Molecular Structure"},"content":{"rendered":"

You can Download Chapter 4 Chemical Bonding and Molecular Structure Questions and Answers, Notes, 1st PUC Chemistry Question Bank with Answers<\/a> Karnataka State Board Solutions help you to revise complete Syllabus and score more marks in your examinations.<\/p>\n

Karnataka 1st PUC Chemistry Question Bank Chapter 4 Chemical Bonding and Molecular Structure<\/h2>\n

1st PUC Chemistry Chemical Bonding and Molecular Structure One Mark Questions and Answers<\/h3>\n

Question 1.
\nWhat is chemical bonding ?
\nAnswer:
\nChemical bonding is the attractive force that holds or binds constituents were atoms, ions or molecules together in a substance.<\/p>\n

Question 2.
\nWhy do atoms combine ?
\nAnswer:
\nAtoms have tendency to attain the stable electronic configuration octet structure of the nearest noble gas in the periodic table.<\/p>\n

Question 3.
\nName the types of chemical bonds.
\nAnswer:
\n(i) Ionic bond
\n(ii) Covalent bond
\n(iii) Co-ordinate bond
\n(iv) Hydrogen bond
\n(v) Metallic bond<\/p>\n

Question 4.
\nNoble gas does not form compounds. Why ?
\nAnswer:
\nNoble gas has stable electronic configuration in the valence shell ns2np6 (octet structure) helium has two electrons only.<\/p>\n

Question 5.
\nWhat is octet rule ?
\nAnswer:
\nThe tendency of atoms of elements to attain octet structure of the nearest noble gas during formation of a chemical bond is known as octet rule.<\/p>\n

\"KSEEB<\/p>\n

Question 6.
\nWhat is meant by octet structure ?
\nAnswer:
\nThe atoms having 8 electrons in the outer most orbit or having valence electronic configuration ns2n p6.<\/p>\n

Question 7.
\nWhy are rare gases are mono atomic ?
\nAnswer:
\nRare gases process octet structure i.e., 8-electrons in the outer most orbit. They have no tendency to react.<\/p>\n

Question 8.
\nGive one molecule that does not obey octet rule.
\nAnswer:
\nHydrogen molecule.<\/p>\n

Question 9.
\nDefine bond length.
\nAnswer:
\nIt is defined as average distance between the centers of nuclei of the two bonded atoms in a molecule.<\/p>\n

Question 10.
\nDefine polarization.
\nAnswer:
\nThe tendency of the anion to get distorted or polarized by the cations is called polarization or polarisability.<\/p>\n

\"KSEEB<\/p>\n

Question 11.
\nBetween AICl3<\/sub> and AIF3<\/sub> which is covalent ?
\nAnswer:
\nAICl3<\/sub>.<\/p>\n

Question 12.
\nName the type of bonds present in ice ?
\nAnswer:
\nCovalent bonds and intermolecular hydrogen bonds.<\/p>\n

Question 13.
\nWhat is the type of hybridization exhibited by Boron in Boron trifluoride ?
\nAnswer:
\nsp2.<\/sub><\/sub><\/p>\n

Question 14.
\nWhat is H-C-H bond angle in methane ?
\nAnswer:
\n109\u00b0 28′.<\/p>\n

Question 15.
\nHow many sigma bonds are present in ethane ?
\nAnswer:
\n\"1st
\nThere are 7a bonds in ethane.<\/p>\n

\"KSEEB<\/p>\n

Question 16.
\nWhat angles are associated with the following orbitals ? sp, sp2 and sp3.
\nAnswer:
\nsp = 180\u00b0
\nsp2<\/sup> = 120\u00b0 ‘
\nsp3<\/sup> = 109\u00b028′<\/p>\n

Question 17.
\nWhat is London forces ?
\nAnswer:
\nIt is a weak force of attraction between non-polar molecules like O2 or N2 (i.e, between like atoms).<\/p>\n

Question 18.
\nMention the type of bond formed between the atoms having same electronegativity.
\nAnswer:
\nCovalent bond.<\/p>\n

Question 19.
\nMention the type of bond formed between the atoms having different electronegativity.
\nAnswer:
\nIonic bond.<\/p>\n

Question 20.
\nWho received noble price for the work on chemical bonds.
\nAnswer:
\nLinus pauling. .<\/p>\n

Question 21.
\nWhat is an ionic bond ?
\nAnswer:
\nAn ionic bond is the electrostatic force of attraction between oppositely charged ions. Or A chemical bond formed by complete transfer of one or more electrons from outermost orbit of electropositive atom to outer most orbit of electronegative atom.<\/p>\n

Question 22.
\nGive an example for ionic crystal ?
\nAnswer:
\nSodium chloride crystal, magnesium chloride.<\/p>\n

Question 23.
\nAmong HF, HC1, HBr and III which has highest ionic character ?
\nAnswer:
\nHF<\/p>\n

\"KSEEB<\/p>\n

Question 24.
\nWhat do you mean by electrovalence ?
\nAnswer:
\nNumber of ions lost (gained) by atoms during the formation of ionic bond.<\/p>\n

Question 25.
\nGive any two factors which favours ionic bond.
\nAnswer:
\nLow ionization energy for metals and high electron affinity of non-metals.<\/p>\n

Question 26.
\nDefine lattice energy.
\nAnswer:
\nThe energy associated when are mole of ionic crystal is formed from its gaseous ions.<\/p>\n

Question 27.
\nWhat you mean by Born-IIaber cycle ?
\nAnswer:
\nIt is cycle of operation needed for the formation of an ionic crystalline solid from its gaseous ions as element.<\/p>\n

Question 28.
\nWhat is meant by covalent bond ?
\nAnswer:
\nA chemical bond formed by the sharing up of one or more electrons between the atoms.<\/p>\n

Question 29.
\nWhat is covalency ?
\nAnswer:
\nNumber of electrons shared between the atoms during covalent bond formation.<\/p>\n

Question 30.
\nWhat is the covalency of CH4<\/sub> ?
\nAnswer:
\n4<\/p>\n

Question 31.
\nWho proposed concept of covalent bond ?
\nAnswer:
\nIn 1916, G.N. Lewin<\/p>\n

Question 32.
\nWhat is the maximum covalency of chlorine ?
\nAnswer:
\n+7<\/p>\n

\"KSEEB<\/p>\n

Question 33.
\nWho proposed valency bond theory ?
\nAnswer:
\nIn 1927, Heitlen and London.<\/p>\n

Question 34.
\nDraw a diagram to show orbital overlap to form a \u03c3 bond.
\nAnswer:
\n\"1st<\/p>\n

Question 35.
\nDraw a diagram to show the orbital overlap to form \u03c0-bond.
\nAnswer:
\n\"1st<\/p>\n

Question 36.
\nDraw a diagram for sigma p-p overlapping.
\nAnswer:
\n\"1st<\/p>\n

Question 37.
\nWhat is a sigma bond ?
\nAnswer:
\nSigma bond is a bond formed by the overlapping of atomic orbital along the axis.<\/p>\n

Question 38.
\nWhat is a pi bond ?
\nAnswer:
\nA bond formed between two atoms by the sideways overlapping of two half filled p-orbitals is called as a pi bond.<\/p>\n

\"KSEEB<\/p>\n

Question 39.
\nHow many sigma and pi bonds are present in an acetylene molecule ?
\nAnswer:
\nH – C = C – H Four sigma bonds and two pi bonds.<\/p>\n

Question 40.
\nHow many pairs of electrons are involved in bond formation in case of nitrogen molecule.
\nAnswer:
\nThree pairs.<\/p>\n

Question 41.
\nWhat is hybridization ?
\nAnswer:
\nIt is a process where two or more atomic orbital of comparable energy of valency shell of an atom mix to form the same number of new orbital of same energy.<\/p>\n

Question 42.
\nMention the overlapping present in
\n(a) H2<\/sub>
\n(b) Cl2<\/sub>
\n(c) HCl
\nAnswer:
\n(a) s – s
\n(b) p – p
\n(c) s – p<\/p>\n

\"KSEEB<\/p>\n

Question 43.
\nHow many electrons are shared in a double bond between two atoms ?
\nAnswer:
\n4 (four)<\/p>\n

Question 44.
\nWhich type of hybridization is called (a) tetrahedral (b>trigonal ?
\nAnswer:
\n(a) sp3<\/sup>, b) sp2<\/sup>.<\/p>\n

Question 45.
\nGive example for two linear molecule.
\nAnswer:
\nEthyne and CO2.<\/sub><\/sub><\/p>\n

Question 46.
\nWho proposed VSEPR theory ?
\nAnswer:
\nIn 1940 by Sidgwick and Powell.<\/p>\n

Question 47.
\nWhat is the structure of ammonia & water molecule ?
\nAnswer:
\nPyramidal and Bent structure respectively.<\/p>\n

Question 48.
\nMention the band angle in Ammonia & H2<\/sub>O,
\nAnswer:
\n107\u00b0 and 104\u00b0 respectively.<\/p>\n

Question 49.
\nWhat is meant by non (homo) polar covalent bond ?
\nAnswer:
\nIn a covalent bond if the pair of electrons shared equally (symmetrically) between the atoms called non-polar covalent bond.<\/p>\n

\"KSEEB<\/p>\n

Question 50.
\nWhat is meant by hetero (polar) covalent bond ?
\nAnswer:
\nIn a covalent bond if the pair of electrons are shared unequally (asymmetrically) between the atoms are called polar covalent bond.<\/p>\n

Question 51.
\nGive example for polar and non-polar molecule.
\nAnswer:
\nPolar HCl, H2<\/sub>O, NH3<\/sub>, Non-polar H2<\/sub>, O2<\/sub>, Cl2<\/sub>.<\/p>\n

Question 52.
\nWrite the relationship between dipole movement and charge.
\nAnswer:
\n\u00b5 = exd (where \u00b5 = dipole moment, e = charge d = distance)<\/p>\n

Question 53.
\nDefine Hydration energy.
\nAnswer:
\nThe energy released when an ionic solid is dissolved is water resulting is polarization of water molecules to form hydrated ions, called hydration energy.<\/p>\n

\"KSEEB<\/p>\n

Question 54.
\nWhat is dipole moment?
\nAnswer:
\nIf is the product of the distances of charge (positive or negative) centres and distance between the centre.<\/p>\n

Question 55.
\nWhich among the following has zero dipole moment BF3<\/sub>, \u00b5H3<\/sub>, H2<\/sub>O ?
\nAnswer:
\nBF3<\/sub><\/p>\n

Question 56.
\nWhat is coordinate bond ?
\nAnswer:
\nIn a chemical bonding both the electrons for sharing between atoms are contributed (donated) by one atom only.<\/p>\n

\"KSEEB<\/p>\n

Question 57.
\nGive one example for the molecule conducting covalent & coordinate bond.
\nAnswer:
\n\"1st<\/p>\n

Question 58.
\nGive one example of a compound containing ionic, covalent and coordinate
\nAnswer:<\/p>\n

Question 59.
\nWhich type of bond formed between NH3 and BF3 ?
\nAnswer:
\nCo-ordinate bond.<\/p>\n

Question 60.
\nWho proposed the concept of co-ordinate bond ?
\nAnswer:
\nG. A. Perkin in 1921.<\/p>\n

Question 61.
\nWhat is hydrogen bond ?
\nAnswer:
\nThe attractive force which binds hydrogen atom of one molecule with electronegative atom present is the same or other molecule is called hydrogen bond.<\/p>\n

\"KSEEB<\/p>\n

Question 62.
\nName two types of hydrogen bonding.
\nAnswer:
\nInter molecular and Intra molecular hydrogen bond.<\/p>\n

Question 63.
\nAt what temperature water has maximum density ?
\nAnswer:
\n4\u00b0C<\/p>\n

Question 64.
\nHow are formic acid molecular are associated ?
\nAnswer:
\nFormic acid molecules are associated with inter molecular hydrogen bonding<\/p>\n

Question 65.
\nName the property by which the dissolution of an ionic solid in water is possible.
\nAnswer:
\nHydrogen bonding.<\/p>\n

Question 66.
\nWhat is Vender Waal\u2019s force ?
\nAnswer:
\nIt is a weak inter atomic or inter molecular force of attractions existing in substances without formation of any chemical bond.<\/p>\n

\"KSEEB<\/p>\n

1st PUC Chemistry Chemical Bonding and Molecular Structure Give Reasons Questions and Answers<\/h3>\n

Question 1.
\nWhy “Ionic bond is formed between alkali metals and halogens” ?
\nAnswer:
\nBecause Alkali metals have low first ionization energy while halogens have high electron affinity.<\/p>\n

Question 2.
\nIonic solids do not conduct electricity.
\nAnswer:
\nIn ionic solids, ions occupy certain fixed positions in the crystal and do not migrate.<\/p>\n

Question 3.
\nIonic compounds are insoluble in ether.
\nAnswer:
\nIonic compounds does not ionize in ether i.e. ether cannot separate the cations and anions of ionic solids.<\/p>\n

Question 4.
\n7\u03c0 bond is weaker than \u03c3 bond.
\nAnswer:
\nIn sigma band the overlapping is maximum where as in pi band the overlapping is minimum-<\/p>\n

Question 5.
\nDipole moment of CO2 is zero.
\nAnswer:
\nIn the linear molecule O = C = O, the dipole due to oxygen from both sides are equal & opposite. As a result dipole moment is zero.<\/p>\n

\"KSEEB<\/p>\n

Question 6.
\nWater molecule has bent structure even it undergoes sp3 hybridization.
\nAnswer:
\nDue to the repulsion between the two lone pair of electrons in water molecule, the structure become bent.<\/p>\n

Question 7.
\nBoiling point of water is very high.
\nAnswer:
\nDue to the presence of intermolecular hydrogen bonding in water.<\/p>\n

1st PUC Chemistry Chemical Bonding and Molecular Structure Two Marks Questions and Answers<\/h3>\n

Give Reason Question:<\/strong><\/p>\n

Question 1.
\n1. Give any two difference between \u03c3 and \u03c0 bond.
\nAnswer:
\n\"1st<\/p>\n

Question 2.
\nMention the \u03c0 and \u03c0 bond present in (1) N2<\/sub> (2) O2<\/sub> (3) C2<\/sub>H4<\/sub> (4) C2<\/sub>H2<\/sub>
\nAnswer:
\n\"1st<\/p>\n

\"KSEEB<\/p>\n

Question 3.
\nWrite any two conditions for (factors favouring) covalent bond.
\nAnswer:
\n1) Two atoms have half filled orbitals
\n2) Shared electrons have opposite spins.
\n3) Overlapping must be maximum.<\/p>\n

Question 4.
\nWhich type of overlapping result in the formation Of (i) sigma bond (ii) pi bond.
\nAnswer:
\n(i) Sigma bond-overlapping of orbital along the axis.
\n(ii) pi bond overlapping sideways of two p-orbital.<\/p>\n

Question 5.
\nWhat is a Bond angle ? Give example.
\nAnswer:
\nIt is defined as the “angle between the oribitals containing bonding electron pairs around the central atom in a molecule or in a complex ion”. It is expressed in degrees. Example : In CO2<\/sub> the bond angle is 180\u00b0. So CO2 has linear shape.<\/p>\n

\"KSEEB<\/p>\n

Question 6.
\nWhat is bond energy ? Give example.
\nAnswer:
\nIt is defined as “the amount of energy required to break one mole of bonds of a particular type in the gaseous state.” It is also called bond dissociation enthalpy. Example : C – C bond enthalpy is 348 kJ mol’1.<\/p>\n

Question 7.
\nWhat is bond order ? Give example.
\nAnswer:
\nIt is the number of covalent bonds holding the atoms in the molecule.
\nExample : If the bond is formed by the sharing of two electron pairs, then the bond order is 2. O = O or C = C bond in alkenes.<\/p>\n

Question 8.
\nCalculate the bond order of Helium.
\nAnswer:
\nHelium contains four electrons. Its electronic configuration is H2
\nBond order = \\(\\frac{1}{2}\\) (nb<\/sub> -na<\/sub>)
\nnb<\/sub> = number of bonding electrons
\nna<\/sub> = number of anti bonding electrons
\n\\(\\frac{1}{2}\\)(2-2) =0
\nSo, He2<\/sub>. does not exist.<\/p>\n

Question 9.
\nExplain Van-der-waals force with example.
\nAnswer:
\nIt can be explain with 3 types.
\n(a) Dipole and Dipole interaction : Dipole – Dipole interaction exists between polar molecules like NH3<\/sub>, SO2<\/sub>, HC1… Greater the dipole interaction greater is Vander Waal’s force. Hence such molecules liquefied easily.
\n(b) Dipole & induced dipole interaction : A permanent dipole molecule can induce polarity in a non-polar molecular when comes near to each other. As a result between polar of non-polar molecule there exists force of attraction.
\n(c) Induced dipole & Induced dipole interaction. Non polar moleculas like, O2<\/sub> and N2<\/sub> having induced polarity on each other which is called Landon forces. When these two molecules comes near to each other the force increases.<\/p>\n

Question 10.
\nExplain the term ‘Hydration of Ions”.
\nAnswer:
\nWhen ionic solid is dissolved in polar solvent like water, the cations & anions of ionic solid is attracted by oxygen and hydrogen of water respectively. As a result each ions surrounded by many number of water molecule to form hydrated ion. This exothermic process is called Hydration.<\/p>\n

* Degree of hydration depends upon the charge density of an ion.
\n\u2022 Degree of hydration decreases as size of ion increases
\nExample : Li+<\/sup> > Na+<\/sup> > K+<\/sup>
\n\u2022 Ionic solid dissolves in water easily, if lattice energy is less than hydration
\nenergy.<\/p>\n

Question 11.
\nGive example for s – p overlapping.
\nAnswer:
\n\"1st<\/p>\n

\"KSEEB<\/p>\n

Question 12.
\nGive example for p – p \u03c3 overlapping.
\nAnswer:
\n\"1st<\/p>\n

Question 13.
\nWhy do C show 4 valency ?
\nAnswer:
\nThe ground state electronic configuration of C is 1s2<\/sup>2s22p2<\/sup>. In exited state, one electron if 2s jumps to 2p, hence the electronic configuration 1s2 2s1<\/sup>2p1<\/sup>x<\/sub> 2p1<\/sup>y<\/sub> 2p1<\/sup>z<\/sub><\/sup><\/sup><\/p>\n

Question 14.
\nDraw the sp3<\/sup>. hybridized C.
\nAnswer:
\nIn sp3<\/sup> hybridization from 1s2<\/sup>2s1<\/sup>2p1<\/sup>x<\/sub> 2p1<\/sup>y<\/sub> 2p1<\/sup>z<\/sub> the orbitals 2s2<\/sup>2p1<\/sup>x<\/sub> 2p1<\/sup>y<\/sub> 2p1<\/sup>z<\/sub> hybridization to give sp3<\/sup> hybridized C as follows.
\n\"1st<\/p>\n

Question 15.
\nDraw the sp2 hybridized C.
\nAnswer:
\nIn sp2<\/sup> hybridization, the 2s1<\/sup>,2p1<\/sup>x<\/sub>,2p1<\/sup>y<\/sub> orbtials hybridization where as 2pz<\/sub> is not involves in hybridization.
\n\"1st
\n<\/sup><\/p>\n

\"KSEEB<\/p>\n

Question 16.
\nDraw the sp hybridized C.
\nAnswer:
\nIn sp hybridized C, the 2s1<\/sup> &2p1<\/sup>x<\/sub> is hybridizes where as 2p1<\/sup>y<\/sub> and 2p1<\/sup>z<\/sub> is not.
\n\"1st<\/p>\n

Question 17.
\nWhat do you mean by lone pair of electron ?
\nAnswer:
\nThe pair of electron which involves in hybridization but not involves in covalent bond formation (involves in co-ordinate bond formation).<\/p>\n

Question 18.
\nMention the condition favouring ionic bond formation.
\nAnswer:<\/p>\n

    \n
  1. Lower Ionisation energy of metals.<\/li>\n
  2. Higher Electron affinity of non – metal<\/li>\n
  3. Higher magnitude of lattice energy of bond<\/li>\n
  4. Higher electromagnativity difference between metal and non-metals.<\/li>\n
  5. Larger radius of cation of smaller radius of anion.<\/li>\n<\/ol>\n

    Question 19.
    \nMention any two characteristics of ionic compounds.
    \nAnswer:<\/p>\n

      \n
    1. They have high Melting point.<\/li>\n
    2. Many of it are solid in nature.<\/li>\n
    3. Does not conduct in solid state but good conductors in fused or aqueous state.<\/li>\n
    4. Soluble in polar solvent & insoluble in non-polar solvent.<\/li>\n
    5. Ionic bond is non-directional.<\/li>\n
    6. They do not exhibit Isomerism.<\/li>\n<\/ol>\n

      \"KSEEB<\/p>\n

      Question 20.
      \nMention the factors favouring covalent bond.
      \nAnswer:
      \nIn covalent molecule the combining atoms should have<\/p>\n

        \n
      1. High ionization energy<\/li>\n
      2. High electron affinity<\/li>\n
      3. Small or equal electronegative<\/li>\n
      4. Smaller atomic size<\/li>\n
      5. Contain unpaired electron with opposition spin<\/li>\n
      6. Attain octect structure.<\/li>\n
      7. Smaller intermolecular distance.<\/li>\n<\/ol>\n

        Question 21.
        \nMention the characteristic of covalent molecule.
        \nAnswer:<\/p>\n

          \n
        1. They are generally gases or liquid or soft solid<\/li>\n
        2. Insoluble in polar solvent & soluble in non polar solvent.<\/li>\n
        3. They do not conduct.<\/li>\n
        4. They always exists in its molecular state but not in ionic state.<\/li>\n
        5. They have fixed direction in space.<\/li>\n
        6. They show isomerism.<\/li>\n
        7. They do not undergoes electrolysis hence called non-electrolytes.<\/li>\n<\/ol>\n

          Question 22.
          \nHow do Vander Waal’s force establishes ?
          \nAnswer:
          \nElectrons in non-polar molecule oscilates (vibrates). As a result the charges will be v conentrated in a region. Hence non-polar molecule becomes momentarily polarized. This polarized molecule shows induced (artificial) dipole moment which attracts the constituents together – results is Vander Wall’s force.<\/p>\n

          \"KSEEB<\/p>\n

          Question 23.
          \nWhat do you mean by Co-ordinate Bond ? Explain with example.
          \nAnswer:
          \nThe bond formed by donation of electron from one of the constituents present in the molecule is called co-ordinate bond.
          \nIt is only directional bond & indicated by ” \u2192 ”
          \nH3<\/sub> \u2192 BF3<\/sub> [Nitrogen donates pair of electrons to form bond] NH3<\/sub>BF3<\/sub><\/p>\n

          Question 24.
          \nHC1 form polar bond.
          \nAnswer:
          \nIn HCl electron is not shared equally, since chlorine is more electronegative than hydrogen and the shared pair shifts more towards chlorine. As a result partially charged H\u03b4+<\/sup> – Cl\u03b4-<\/sup> result polarity.<\/p>\n

          Question 25.
          \nIonic solid do not conduct.
          \nAnswer:
          \nIn it the ions occupy certain fixed lattice positions in the crystals and do not move. Hence they do not conduct.<\/p>\n

          Question 26.
          \nNH3<\/sub> polar but BF3<\/sub> non-polar.
          \nAnswer:
          \nAmmonia has dipole moment due to pyramidal structure but is BF3<\/sub> the dipole moment is zero due to symmetrical planar structure.<\/p>\n

          \"KSEEB<\/p>\n

          Question 27.
          \nHF is liquid where as HCl, HBr…. Other hydrogen halide is liquid.
          \nAnswer:
          \nSince F is highly electronegative, name there exists powerful inter molecular hydrogen bonding in HF results in liquid state.<\/p>\n

          Question 28.
          \nO-Nitrophenol is more volatile than p-Nitrophenol (Or) boling point of p- nitriphenol is greater than O-nitrophenol)
          \nAnswer:
          \nIn O-nitrophenol there exists intra molecular hydrogen bonding within the molecule where as in p-nitrophenol there exists inter molecular hydrogen bonding between the molecule.<\/p>\n

          Question 29.
          \nCovalent compounds have law melting point.
          \nAnswer:
          \nIn covalent compound molecules are held together by weak intermolecular forces.<\/p>\n

          Question 30.
          \nH2<\/sub>O is liquid whereas H2<\/sub>S is gas.
          \nAnswer:
          \nIn H2<\/sub>O, hydrogen is combines with highly electronegative element and also forms inter molecular hydrogen bond. But S is less electronegative and in H2<\/sub>S there is no hydrogen bonding.<\/p>\n

          Question 31.
          \nC – H bond is polar but CH4 is non polar.
          \nAnswer:
          \nMethane has symmetrical tetrahedral structure hence dipole moment is zero.
          \nTherefore it is non polar.<\/p>\n

          Question 32.
          \nDensity of water is maximum at 4\u00b0C.
          \nAnswer:
          \nAlong with covalent bond and hydrogen bond, H2<\/sub>O molecule exists in best form from tetrahydral from state by leaving vacant space. When heated from 0\u00b0C > 4\u00b0C the \u2018 hydrogen bond brakes and H2<\/sub>O modecule comes closer. As a result density increases to maximum at 0\u00b0C. From 4\u00b0C above, due to heat examples takes place by braking the the destroy decreases.<\/p>\n

          \"KSEEB<\/p>\n

          Question 33.
          \nWater is polar in nature.
          \nAnswer:
          \nEven though sp3<\/sup> hybridization is there is H2<\/sub>O but due to lone pair – lone pair replace
          \nthere exists.<\/p>\n

          Question 34.
          \nWater has high boiling point.
          \nAnswer:
          \nDue to intermolecular hydrogen bonding, water has high boiling point.<\/p>\n

          Question 35.
          \nIce floats on water or ice is lighter than water.
          \nAnswer:
          \nAlong with covalent bond & hydrogen bond, ice form of water exists in the tetrahydral shape from bent structure by leaving vacant space. Due to this vacant space is ice if floats in water.<\/p>\n

          Question 36.
          \nCO2<\/sub> and C2<\/sub>H2<\/sub> (acetylene) are non-polar.
          \nAnswer:
          \nBecause both have linear structure.<\/p>\n

          Question 37.
          \n\u03c3 bond is stronger compare to \u03c0 bond.
          \nAnswer:
          \nIn a \u03c3 bond the overlapping is along the axis and is maximum extent. Where as \u03c0 bond overlapping is sidewise and overlapping is minimum.<\/p>\n

          \"KSEEB<\/p>\n

          Question 38.
          \nEthyl alcohol is an organic compound but still freely soluble in water explain.
          \nAnswer:
          \nThe solubility of ethyl alcohol in water is due to the presence of intermolecular hydrogen bonding between the two.
          \n\"1st
          \nEnergy is released during the attraction this helps in the dissolution of alcohol in water.<\/p>\n

          Question 39.
          \nNitrogen and chlorine have the same electro negativity but only former forms hydrogen bonds. Explain.
          \nAnswer:
          \nBoth these elements have the same elecro negativity (3.0). But the size of nitrogen . atom (atomic radius = 75pm) is smaller than that of chlorine (atomic radius = 99pm). As a result nitrogen atom can cause greater polarization of N – H bond than the Cl atom in Cl – H bond. Thus hydrogen bonding is present in H – H bonds (e.g., NH3<\/sub>) but not in a – H bonds (eg. HCl)<\/p>\n

          1st PUC Chemistry Chemical Bonding and Molecular Structure Three Marks Questions and Answers<\/h3>\n

          Question 1.
          \nExplain the formation of Ionic bond in NaCl.
          \nAnswer:
          \nSodium has electronic configuration 1s2<\/sup> 2s2<\/sup> 2p6<\/sup> 3s1<\/sup>, when it looses one electron,
          \nattains stability where as chlorine 1s2<\/sup>2s2<\/sup>2p6<\/sup>3s2<\/sup>3p5<\/sup>, it gain one electron to get stability.
          \n\u2234 The electron lost by Na is gained by the chlorine forming ionic bond.
          \n\"1st<\/p>\n

          Question 2.
          \nWrite the Barn Haber cycle for the formation of NaCl.
          \nAnswer:
          \n\"1st
          \nWhen U = Lattice energy ; \u2206HS<\/sub> – Enthalpy for sublimation, \u2206Hi<\/sub> = Enthalpy of ionization, \u2206Hd<\/sub> = enthalpy of dissociation, \u2206HEa<\/sub> = Enthalpy for electron affinity.
          \nThe only one step for formation of NaCl from sodium and chlorine is associated with the energy called = \u2206Hf<\/sub> = enthalpy of formation.
          \n\u2206Hf<\/sub> = U + \u2206HS<\/sub> + \u2206Hi<\/sub> + \u2206Hd<\/sub> + \u2206HEa<\/sub>
          \n\u2234 Lattice energy U = \u2206Hf<\/sub>= [\u2206HS<\/sub> + \u2206Hi<\/sub> + \u2206Hd<\/sub> + \u2206Hta<\/sub> ]<\/p>\n

          \"KSEEB<\/p>\n

          Question 3.
          \nExplain the steps involved in Born Haber cycle for the formation of NaCl.
          \nAnswer:
          \nStep 1 : Sublimation of metallic sodium of gaseous sodium atom with enthalpy of
          \nsublimation = \u2206HS<\/sub>
          \n\"1st<\/p>\n

          Step – 2 : Dissociation of molecule of chlorine to chlorine atoms with enthalpy of dissociation = \u2206Hd<\/sub>
          \n\"1st<\/p>\n

          Step – 3 : Ionization of gaseous sodium with enthalpy of ionization = \u2206Hi<\/sub>
          \n\"1st<\/p>\n

          Step – 4 : Addition of electron to gaseous chlorine atom with enthalpy of electron affinity = \u2206HEa
          \n\"1st<\/p>\n

          Step – 5: Close packing of gaseous sodium ion and chloride ion to form lattice structure of NaCl, with lattice chloride ion to form lattice structure of NaCl, with
          \nLattice energy = U; NaCl+<\/sup>(g) + Cl–<\/sup>(g) \u2192 NaCl\u2206; \u2206H = U<\/p>\n

          Step – 6 : But sum of all the energies will be equal to the heat of formation of one mole of sodium chloride form its reluctant i.e., \u2206Hf
          \nNa(s) + 1\/2Cl2<\/sub>(g) >NaCl(s);\u2206H = \u2206Hf<\/sub><\/p>\n

          Question 4.
          \nDefine hybridization ? Explain the hybridization in Methane molecule.
          \nAnswer:
          \nCH4<\/sub> – Methane Molecule.
          \nIt is a process where two or more atomic orbital of comparable energy of valency shell of an atom mix to form the same number of new orbital of same energy.<\/p>\n

          The Molecular formula of Methane is CH4
          \nElectronic configuration of C is ground state – 1s2<\/sup>2s2<\/sup>2p2<\/sup>.
          \nElectronic configuration of C in excited state – 1s2<\/sup>2s1<\/sup>2p3<\/sup>
          \nValance orbital representation –
          \n\"1st
          \nThe valence orbital contains impaired electron. Hence sp3<\/sup> hybridized carbon combine with 4 hydrogen atom forms methane molecule.<\/p>\n

          \"KSEEB<\/p>\n

          Question 5.
          \nExplain sp2<\/sup> hybridization in ethane molecule. C2<\/sub>H4<\/sub> – ethene.
          \nAnswer:
          \nThe molecular formula of ethene is C2<\/sub>H4<\/sub>
          \nElectronic configuration of C is ground state – 1s2<\/sup> 2s2<\/sup> 2p2<\/sup>
          \nElectronic configuration of C is excited state – 1s2<\/sup>2s1<\/sup>2p3<\/sup>
          \nValence orbital representation
          \n\"1st
          \nsp2<\/sup> hybridization involves 2 carbon atoms combines with 4 atoms of hydrogen.
          \nIn ethane molecule, there is 5 sigma and 1 pi bond. The angle of sp2<\/sup> hybridized ethane is 120\u00b0.<\/p>\n

          Question 6.
          \nExplain sp2<\/sup> hybridization BF3<\/sub> molecule.
          \nAnswer:
          \nBF3<\/sub> molecule
          \nElectronic configuration of B – 1s2<\/sup> 2s2<\/sup> 3P1<\/sup>
          \nValance orbital representation
          \n\"1st
          \nElectronic configuration of F – 1s2<\/sup> 2s2<\/sup> 2P5<\/sup>
          \nValance orbital representation
          \nOnly one unpaired electrons is present in fluorine. Hence only 2pz orbital of fluorine involved in bond formation.
          \nStructure – triangular planar.<\/p>\n

          Question 7.
          \nExplain sp hybridisation with an example.
          \nAnswer:
          \nC2<\/sub>H2<\/sub> – ethyne or acetylene
          \nElectronic configuration of C is ground state -1s2<\/sup> 2s2<\/sup> 2P2<\/sup>
          \nElectronic configuration of C excited state – 1s2<\/sup> 2s2<\/sup> 2P3<\/sup>
          \nValance orbital representation
          \n\"1st
          \nSp hybridised, C contains 2 impaired electron and one each in py and pz two sp hybridised C combines with two 1s1<\/sup> orbital of H.
          \nTwo more hybrid orbitals each carbon overlap with Is atomic orbitals of hydrogen to form sigma bonds. The unhybridised 2pz orbitals of both the carbon atoms now overlap sideways to form carbon-carbon pi-bond.<\/p>\n

          Question 8.
          \nExplain valence Shell Electron Pair Repulsion (VSEPR) theory.
          \nAns:
          \nBonding s The bond formation takes place if there exists impaired electron in the valance shell.<\/p>\n

            \n
          • Shape : The geometry or the shape of a molecule depends on the number of valence shell electrons surroundings the central atom.<\/li>\n
          • Repulsion : Electron pair tend to repell one another because electron clouds have similar charge.
            \nStability s As a result of electron pair repulsion these electron pairs try to stay apart as possible in order to attain minimum energy and maximum stability.<\/li>\n
          • Repulsive interaction : Lane pair with lane pair electrons are having maximum repulsive interaction, bond pair – bond pair electrons are having minimum repulsive interaction.<\/li>\n
          • When angle of repulsion decreases angle between the electron pair increases.
            \n(109\u00b0. 28′ less repulsion, 104\u00b0 more repulsion)<\/li>\n<\/ul>\n

            \"KSEEB<\/p>\n

            Question 9.
            \nBased on VSEPR theory explain the structure of ammonia.
            \nAnswer:
            \nAmmonia (NH3<\/sub>)
            \nElectronic configuration of N : 1s2<\/sup> 2s2<\/sup> 2p3<\/sup>
            \nValance orbital representation
            \n\"1st
            \n1. When 2s2<\/sup> orbital hybridised with 2px<\/sub>, 2py<\/sub> and 2pz<\/sub> forms the following sp3<\/sup> hybridised structure..
            \n2. In 2s2<\/sup> orbital, the electrons are paired up hence they are not involved in bond formation called loan paired of electron (L.P).
            \n3. When sp3<\/sup> hybridized N combines with 3 hydrogen atom, forms pyramidal structure of ammonia.
            \nPyramidal structure angle = 107\u00b0<\/p>\n

            Question 10.
            \nBased on VSEPR theory explain the structure of water.
            \nAnswer:
            \nElectronic configuration of O: 1s2<\/sup>2s2<\/sup>2p4<\/sup>
            \nValence orbital representation:
            \n\"1st
            \n1. When 2s2<\/sup> orbital hybridised with 2sx<\/sub>, 2py<\/sub> and 2pz<\/sup> forms the following sp3<\/sup> hybridisation structure.
            \n2. In 2s2<\/sup> and 2px<\/sub>2<\/sup> , the electrons are paired up hence they are not involved in bond formation called loan paired of electron (L.P.)
            \n3. When sp3<\/sup> hybridised O combines with 2 hydrogen atom forms Bond structure water.<\/p>\n

            Question 11.
            \nWhat are polar and Non Polar covalent bond explain with example.
            \nAnswer:
            \nPolar covalent molecules : In diatomic covalent molecule, the shared pair of electrons is displaced towards more electronegative atom present in the molecule is called polar covalent molecule. Example : HC1
            \nChlorine pulls the shared electron from hydrogen towards itself. Hence it is polar molecule.
            \nH2<\/sub>O
            \nOxygen pulls the shared pair of electron from two hydrogen atom surrounding it. Hence it is a polar molecule.
            \nNon Pollar covalent bond : In diatomic covalent molecule, the shared pair of electron is equally distributed between the atoms in the molecule.
            \nExample: H2<\/sub>, O2<\/sub>, N2<\/sub>, O3<\/sub> etc.<\/p>\n

            \"KSEEB<\/p>\n

            Question 12.
            \nDefine dipole moment ? Comment on structure & dipole moment of CO2<\/sub>, BF3<\/sub>
            \nAnswer:
            \nIt is the product of electric charge and distance between the positive and negative species present in the molecule.
            \n\"1st
            \nThe combining atom should attain octect structure by sharing one or more electron.<\/p>\n

            Question 13.
            \nDefine Hydrogen Bond ? Explain its type with example.
            \nAnswer:
            \nElectrostatic force of attraction that exists between hydrogen atom of one molecule and electronegative atom of same or other molecule is called hydrogen bond.
            \nType of hydrogen bond :<\/p>\n

              \n
            1. Intermolelcular hydrogen bond.<\/li>\n
            2. Intramolecular hydrogen bond.<\/li>\n<\/ol>\n

              1. Intermolecular hydrogen bond : Electrostatic force of attraction that exists between hydrogen atom of one molecule and electronegative atom of another molecule is called intermolecular hydrogen atom.
              \n1. H2<\/sub>O .
              \n\"1st
              \n2. Intramolecular Hydrogen bond : Electrostatic force of attraction that exists between hydrogen atom of one molecule electronegative atom of the same molecule. Example : Salicylic acid C6<\/sub>H4<\/sub>COOH(OH)
              \n\"1st<\/p>\n

              1st PUC Chemistry Chemical Bonding and Molecular Structure Four \/ Five Marks Questions and Answers<\/h3>\n

              Question 1.
              \nExplain Valence Bond Theory.
              \nAnswer:<\/p>\n

                \n
              • The covalent bond is formed by overlapping of those orbital which contains impaired electrons.<\/li>\n
              • When the overlapping is along axis, the overlapping becomes maximum and strong, called as o sigma bond.<\/li>\n
              • During overlapping, the electron present in the valance orbit must have opposite spin.<\/li>\n
              • Covalent molecule have lower energy than combining atoms. Therefore resulting molecule are always stable.
                \nThe extent of overlapping is ss > s-p > p-p.<\/li>\n<\/ul>\n

                Question 2.
                \nSalient features of Molecular Orbital Theory (MOT). ‘
                \nAnswer:<\/p>\n

                  \n
                • The electrons in an atom are found in atomic orbitals, the electrons in a molecule are found in molecular orbitals.<\/li>\n
                • The molecular orbitals are formed by the combination of atomic orbitals of comparable energies and proper symmetry.<\/li>\n
                • The BMO has lower energy and hence greater stability than the correspondinb ABMO.<\/li>\n
                • The molecular orbitals are filled by electrons in accordance with Auibau principle, Pauli’s exclusion principle and the Hund’s rule.<\/li>\n<\/ul>\n

                  \"KSEEB<\/p>\n","protected":false},"excerpt":{"rendered":"

                  You can Download Chapter 4 Chemical Bonding and Molecular Structure Questions and Answers, Notes, 1st PUC Chemistry Question Bank with Answers Karnataka State Board Solutions help you to revise complete Syllabus and score more marks in your examinations. Karnataka 1st PUC Chemistry Question Bank Chapter 4 Chemical Bonding and Molecular Structure 1st PUC Chemistry Chemical …<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[81],"tags":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/posts\/8904"}],"collection":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/comments?post=8904"}],"version-history":[{"count":0,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/posts\/8904\/revisions"}],"wp:attachment":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/media?parent=8904"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/categories?post=8904"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/tags?post=8904"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}