1 1st Year Chemistry Guess 2018 All Punjab Boards Important MCQs Which statement is not true A Isotopes with even atomic masses are comparatively abundant B Isotopes with odd atomic masses are comparatively abundant C Isotopes even atomic masses and even atomic numbers are comparatively abundant D Isotopes with even atomic masses and odd atomic numbers are comparatively abundant Silver has isotopes 9 16 17 18 Whith statement is not correct about galvanic cell A Anode is negatively charged B Reduction occurs at anode C Cathode is positively charged D Reduction occurs at cathode Which statement about the following equilibrium is correct 2S02 g 02 0 77 2S03 g AH 188 3 KJ mole A The value of Kp falls with rise in temperature B The value of Kp falls with increase in pressure C Adding V205 catalyst increases the equilibrium yield of sulphur trioxide D The value Kp Ke A substance which makes the catalyst more effective is called A Inhibitor B Retarder C Promoter D Auto Catalyst The mass of two moles of electrons is A 1 10 mg B 1 008 mg C 0 184 mq D 1 673 mg 2 7 g of At will react completely with how much mass of 02 to produce At203 A 0 8 g of oxygen B 1 6 g of oxygen C 3 2 g of oxygen D 2 4 g of oxygen Mass of one mole of electron is A 1 008 mg B 0 55 mg C 1 84 mg D 1 673mg 0 1 mole of solute dissolved in 100g of the solvent will be A 0 1 molal B 1 0 molal C 0 5 molal D None of these Solvent extraction method is particularly useful technique for separation when the product to be separated is A Non volatile or thermally unstable B Volatile or thermally stable C Non volatile or thermally stable D Volatile or thermally unstable Solvent extraction is an equilibrium process and it is controlled by A Law of mass action B Distribution law C The amount of solvent used D The amount of solute Regards SYED ATEEB M Sc M A B Ed 0301 4870705 2 Law of mass action was derived by Gulberg and wage in A 1909 B 1906 C 1846 D 1864 In solvent extraction the law applied is A Law of mass action B Distribution law C Coulomb s law D Boyle s law Solvent extraction is a process A Exothermic B Endothermic C Equilibrium D Non equilibrium London dispersion forces are the only forces present among the A Molecules of water in liquid state B Atoms of helium in gaseous state at high temperature C Molecules of solid iodine D Molecules of hydrogen chloride gas The molecules of CO2 in dry ice form the A Ionic crystals B Covalent crystals C Molecular crystals D Any type of crystals Which of the following molecules has zero dipole moment A NH3 B CFICei C H2O D BF3 The most stable elements are A Halogens B Lithium family C Noble gases D None of these Bond angle I in case of ammonia molecule is A 105 B 107 5 C 120 D 180 The number of bonds in oxygen molecule is A One a and one 7 B One a and two 7 C Three sigma only D Two sigma only In dry ice CO2 molecules form A Ionic crystals B Covalent crystals C Molecular crystals D Any type of crystals Escape out of gas molecules one by one through tiny hole is A Diffusion B Effusion C Osmosis D All of these Regards SYED ATEEB M Sc M A B Ed 0301 4870705 3 The four equivalents SP3 hybrid orbitals in space are at an angle of A 120 B 107 5 C 104 5 D 109 5 Angstrom is the unit of A Time B Lengthy A Mass A Frequency A 3 6 gmH20 B 4 8 gm C2H5OH C 2 8 gm CO D 5 8 gm N205 Largest number of molecules are in Which molecule has zero dipole moment A NH3 B CHC 3 C H2O D BF3 An orbital which is spherical and symmetrical is A s orbital B p orbital A d orbital A f orbital Quantum number values for 21 orbitals are A n 2 1 B n 1 2 C n 1 0 D n 2 t 0 The nature of positive rays depends on A The nature of electrode B The nature of discharge tube C The nature of residual gas D The temperature Cathode in NICAD is A Ag2O B N102 C Cd D Zn Cathode rays strike alumina and produce a colour A Red B Blue C Yellow D Green Positive ions are called A cations B Annions C Molecules D Hydrated ions The e value for the positive rays is maximum for A Hydrogen B Helium C Oxygen D Nitrogen Regards SYED ATEEB M Sc M A B Ed 0301 4870705 4 An ionic compound A 13 is most likely to be formed when A The ionization energy of A is high and electron affinity of B is low B The ionization energy of A is low and electron affinity of B is high C Both the ionization energy of A and electron affinity of B are high D Both the ionization energy of A and electron affinity of B are low Which of the hydrogen halide has the highest percentage of ionic character A HI B HBr C HCC D HF CsF has ionic character A 60 B 80 C 92 D 100 Ionic product of water Kw increases when temperature increases from 0 C to 100 C A 25 times B 75 times C 55 times D 65 times Formation of chemical bond takes place when A Energy is absorbed B Forces of repulsion overcome forces of attraction C Forces of attraction are equal to forces of repulsion D Forces of attraction overcome forces of repulsion Which species has unpaired electrons in anti bonding molecular orbitals A 022 B 022 C B2 D F2 For a given process the heat changes at constant pressure qp and at constant volume qv are related to each other as A qp qv B qp qv C qp D qp c 1 2L The change in heat energy of a chemical reaction at constant temperature and pressure is called A Enthalpy change B Heat of sublimation C Bond energy D Internal energy change Which solution has the highest boiling point A 5 85 solution of sodium chloride B 18 00 solution of glucose C 6 00 solution of urea D all have the same boiling point The boiling point of water at the top of Mount Everest is A 59 C B 69 C C 83 C D 75 C In order to mention the boiling point of water at 110 C the external pressure should be A Between 760 torr and 1200 torni B Between 200 torr and 760 tor C 100 torr D Any value of pressure Regards SYED ATEEB M Sc M A B Ed 0301 4870705 5 Oxidation state of chromium in K2CrO4 is A …