Chem Lec Quizzes And Exams PDF

**Chem Lec Quizzes And Exams** - a\) 2Na + Cl2 → 2NaCl b\) N2 + 3H2 → 2NH3 c\) 2SO3 → 2SO2 + O2 d\) AgNO3 + NaCl → AgCl + NaNO3 **Ans: D** \(a) The oxidation number of hydrogen is always +1. \(b) The algebraic sum of all the oxidation numbers in a compound is zero. \(c) An element in the...

**Chem Lec Quizzes And Exams** - a\) 2Na + Cl2 → 2NaCl b\) N2 + 3H2 → 2NH3 c\) 2SO3 → 2SO2 + O2 d\) AgNO3 + NaCl → AgCl + NaNO3 **Ans: D** \(a) The oxidation number of hydrogen is always +1. \(b) The algebraic sum of all the oxidation numbers in a compound is zero. \(c) An element in the free or the uncombined state bears oxidation number zero. \(d) In all its compounds, the oxidation number of fluorine is -1. **Ans: A** \(a) 0, +1, -2 \(b) +2, +1, -2 \(c) 0, +1, +2 \(d) -2, +1, -2 **Ans: A** \(a) 4, 3, 1, 5 \(b) 1, 5, 3, 7 \(c) 1, 3, 4, 5 \(d) 3, 5, 7, 1 **Ans: C** \[Cr (P Ph3) (CO)3\] is \(a) + 3 \(b) +8 \(c) Zero \(d) +5 **Ans: C** \(a) A3(BC4)2 \(b) A3(B4C)2 \(c) ABC2 \(d) A3(BC3)2 **Ans: A** xCl2 + 6OH-- → ClO−3 + yCl-- + 3H2O are \(a) x = 2, y = 4 \(b) x = 5, y = 3 \(c) x = 3, y = 5 \(d) x = 4, y = 2 **Ans: C** A\) Na B\) Cl₂ C\) NaCl D\) None of the above **Ans: A** a\) Oxidized from +7 to +2 b\) Reduced from +7 to +2 c\) Oxidized from +2 to +7 d\) Reduced from +2 to +7 **Ans: B** \(a) CaCO3 → CaO + CO2 \(b) O2 + 2H2 → 2H2O \(c) Na + H2O → NaOH + 1/2H2 \(d) MnCl3 → MnCl2 + 1/2 Cl2 **Ans: A** 3Br2 + 6CO32- + 3H2O → 5Br -- + BrO3-- + 6HCO3-- \(a) Bromine is oxidised and carbonate is reduced. \(b) Bromine is reduced and water is oxidised. \(c) Bromine is neither reduced nor oxidised. \(d) Bromine is both reduced and oxidised. **Ans: D** Cr2O72- + Fe2+ + C2O42- → Cr3+ + Fe3+ + CO2 (Unbalanced) \(1) 3 \(2) 4 \(3) 5 \(4) 6 **Ans: 4** A\) Oxidation involves a decrease in oxidation state. B\) Reduction involves a decrease in oxidation state. C\) Oxidation involves a decrease in the number of oxygen atoms. D\) Reduction involves a decrease in the number of hydrogen atoms **Ans: B** xMnO4--+ yC2O42- +zH+ → xMn2+ + 2yCO2+(z/2)H2O The values of x, y and z in the reaction are respectively :- \(1) 5, 2 and 16 \(2) 2, 5 and 8 \(3) 2, 5 and 16 \(4) 5, 2 and 8 **Ans: 3** A\) NaCl + H₂O → NaOH + HCl B\) HCl + NaOH → NaCl + H₂O C\) CaCO₃ → CaO + CO₂ D\) CH₄ + 2O₂ → CO₂ + 2H₂O **Ans: D** \(a) NaCl + KNO3 → NaNO3 + KCl \(b) CaC2O4 + 2HCl → CaCl2 + H2C2O4 \(c) Mg(OH)2 + 2NH4Cl → MgCl2 + 2NH4OH \(d) Zn + 2AgCN → 2Ag + Zn (CN)2 **Ans: D** The values of X, Y and Z in the above redox reaction are respectively : \(1) 2, 1, 3 \(2) 3, 1, 6 \(3) 2, 1, 2 \(4) 3, 1, 4 **Ans: 2** A\) KMnO₄ B\) H₂SO₄ C\) H₂C₂O₄ D\) CO₂ **Ans: A** \(a) CuO + H2 → Cu + H20 \(b) Fe202 + 3CO → 2Fe + 3C02 (c).2K + F2 →2KF \(d) BaCl2 + H2S04 →BaS04 + 2FIC1 **Ans: D** \(1) H2O2 + 2H+ + 2e-- → 2H2O \(2) H2O2 -2e-- → O2+2H+ \(3) H2O2 + 2e-- → 2OH-- \(4) H2O2 + 2OH-- -2e-- → O2 + 2H2O \(1) (1), (3) \(2) (2), (4) \(3) (1), (2) \(4) (3), (4) **Ans: 2** \(a) H2SO4 + 2NaOH → Na2SO4 + 2H2O \(b) BaCl2 + H2SO4 → BaSO4 + 2HCl \(c) CH3COOH + C2H5OH → CH3COOC2H5 + H2O \(d) 2FeCl3 + SnCl2 → 2FeCl2 + SnCl4 **Ans: D** MnO−4 + C2O2−4 + H+ → Mn2+ + CO2 + H2O correct stoichiometric coefficients of MnO−4, C2O2−4, H+ are \(a) 2, 5, 16 \(b) 16, 5, 2 \(c) 5, 11, 2 \(d) 2, 16, 5 **Ans: A** A\) MnO₄⁻ B\) H⁺ C\) C₂O₄²⁻ D\) Mn²⁺ **Ans: A** H2SO3(aq) + Sn4+(aq) + H2O(l) → Sn2+(aq) + HSO4--(aq) + 3H+(aq) Which of the following statements is correct? \(1) H2SO3 is the reducing agent because it undergoes oxidation \(2) H2SO3 is the reducing agent because it undergoes reduction \(3) Sn4+ is the reducing agent because it undergoes oxidation \(4) Sn4+ is the oxidizing agent because it undergoes oxidation **Ans: 1** Zn + Cu2+ → Zn2+ + Cu With reference to the above, which one of the following is the correct statement? \(a) Zn is reduced to Zn2+ ions. \(b) Zn is oxidised to Zn2+ ions. \(c) Zn2+ ions are oxidised to Zn. \(d) Cu2+ ions are oxidized to Cu. **Ans: B** - 1. A\) Increase B\) Decrease C\) No change D\) Initially increase then decrease **Ans: B** 2. A\) It can predict the feasibility of a battery. B\) It calculates the exact amount of reactants used. C\) It helps in determining the cell potential under varying conditions. D\) It incorporates the effects of concentration and temperature on cell potential. **Ans: B** 3. A\) Joules B\) Volts C\) Coulombs D\) Moles **Ans: C** 4. If the cell potential is zero, what does the Nernst equation tell us about the reaction? A\) The reactants and products are in equilibrium. B\) The reaction is very rapid. C\) There are no ions present. D\) It is operating under non-standard conditions. **Ans: A**\ 5. What is the implication of a 'negative' cell potential in the context of the Nernst equation? A\) The cell is not feasible. B\) The reaction is spontaneous. C\) The reaction is non-spontaneous. D\) The cell operates under standard conditions **Ans: C** 6\. What is the EMF of a galvanic cell if the standard oxidation potential of the oxidation half-reaction is 0.64 volts and the standard reduction potential of the reduction half-reaction is 0.48 volts? a\) 1.48 volts b\) 1.12 volts c\) 1.36 volts d\) 0.96 volts **Ans: B** 7\. The standard reduction potentials of X, Y, Z metals are 0.52, -3.03, -1.18 respectively. The order of reducing power of the corresponding metals is: \(a) Y \> Z \> X \(b) X \> Y \> Z \(c) Z \> Y \> X \(d) Z \> X \> Y **Ans: A** 8\. Which of the following statements about the salt bridge in a galvanic cell is correct? a\) It allows the flow of electrons between the electrodes. b\) It completes the circuit and maintains electrical neutrality in the half-cells. c\) It prevents the migration of ions in the solution. d\) It provides a barrier to the flow of current. **Ans: B** 9\. The emf of the cell: Ni / Ni2+ (1.0 M) // Au3+ (1.0 M) / Au (E° = -0.25 V for Ni2+/Ni; E° = 1.5 V for Au3+/Au) is \(a) 1.25 V \(b) -1.25 V \(c) 1.75 V \(d) 2.0 V **Ans: C** 10\. The standard electrode potential (E°) of a half-cell is measured under standard conditions, which include: A\) Concentration of 1 M for all species. B\) Pressure of 1 atm for all gases involved. C\) Temperature of 25°C (298 K). D\) All of the above. **Ans: D** 11\. A) Rydberg constant B\) Gas constant C\) Reaction quotient D\) Rate constant **Ans: B** 12\. The standard reduction potential (E°) of a half-cell reaction is a measure of: a\) The rate of the reaction b\) The stoichiometry of the reaction c\) The electrode potential of the half-cell d\) The equilibrium constant of the reaction **Ans: C** 13\. Find the number of electrons transferred in the equation Cu(g) + 2Ag+(aq) → Cu2+(aq) + 2Ag(s). a\) 4 b\) 3 c\) 2 d\) 1 **Ans: C** 14\. What is the EMF of a galvanic cell if E°cathode = 0.80 volts and E°anode = -0.76 volts? a\) 1.56 volts b\) 0.04 volts c\) -1.56 volts d\) -0.04 volts **Ans: A** 15\. The cell potential (E°cell) for a galvanic cell is given by the formula: A\) E°cell = E°cathode -- E°anode B\) E°cell = E°anode -- E°cathode C\) E°cell = E°anode + E°cathode D\) E°cell = E°cathode × E°anode **Ans: A** 16\. If E°Fe2+/Fe = -0.441 V and E°Fe2+/Fe2+ = 0.771 V, the standard EMF of the reaction, Fe + 2Fe3+ → 3Fe2+ will be \(a) 1.212 V \(b) 0.111 V \(C) 0.330 V \(d) 1.653 V **Ans: A** 17\. In a galvanic cell, the salt bridge is used to: 1. 2. 3. 4. **Ans: 4** 18\. For the electro-chemical cell: M\| M+\|\| X--\| X, E0M+,M = 0.44 V and E0x,x− = 0.33 V From the data one can deduce that \(a) M+ X → M+ + X-- is the spontaneous change \(b) M+ + X-- → M + X is the spontaneous reaction \(c) Ecell = 0.77 V \(d) Ecell = -0.77 V **Ans: B** 19\. When equilibrium is reached inside the two half-cells of the electrochemical cells, what is the net voltage across the electrodes? a\) \> 1 b\) \< 1 c\) = 0 d\) Not defined **Ans: C** 20\. While charging the lead storage battery (a)PbSO4 anode is reduced to Pb (b)PbSO4 cathode is reduced to Pb (c)PbSO4 cathode is oxidized to Pb (d)PbSO4 anode is oxidized to Pb02 **Ans: B** 21\. What is the number of electrons transferred in an equation if the Nernst equation is E(cell) = E°(cell) -- 9.83 × 10-3 × log10 (Anode / Cathode)? a\) 2 b\) 6 c\) 4 d\) 1 **Ans: B** 22\. The e.m.f and the standard e.m.f of a cell in the following reaction is 5 V and 5.06 V at room temperature, Ni(s) + 2Ag+No → Ni2+(0.02M) + 2Ag(s). What is the concentration of Ag+ ions? a\) 0.0125 M b\) 0.0314 M c\) 0.0625 M d\) 0.0174 M **Ans: D** 23\. In the context of electroplating, how does the Nernst equation assist in process optimization? A\) By determining the voltage needed. B\) By setting the temperature of the solution. C\) By calculating the thickness of the plating. D\) By estimating the time required for plating. **Ans: A** 24\. In a galvanic cell, electron flow will be from: 1. 2. 3. 4. **Ans: 1** 25\. Calculate the electrode potential of the given electrode. Pt, Cl2(2 bar)\| 2Cl--(0.02 M); E°(Cl2 \| 2Cl--) = 3.4 V a\) 3.51 V b\) 3.55 V c\) 1.26 V d\) 2.95 V **Ans: A** 26\. What is the standard reduction potential of the cathode of a galvanic cell if the standard EMF of the cell and the standard reduction potential of the anode are 2.71 and -2.37 respectively? a\) 0.68 volts b\) -0.68 volts c\) -0.34 volts d\) 0.34 volts **Ans: D** 27\. Which of the following statements about corrosion is correct? a\) Corrosion is a reduction process. b\) Corrosion only occurs in the presence of air. c\) Corrosion can be prevented by using a metal with a lower reduction potential. d\) Corrosion is a reversible process. **Ans: C** 28\. The reduction potential of a half-reaction is a measure of: A\) The tendency of a substance to gain electrons. B\) The tendency of a substance to lose electrons. C\) The concentration of the reactants in a redox reaction. D\) The pressure of the reactants in a redox reaction. **Ans: A** 29\. What is the EMF of a galvanic cell if the standard reduction potential of the reduction half-reaction is -0.38 volts and the standard reduction potential of the oxidation half-reaction is 0.52 volts? a\) -0.9 volts b\) -0.6 volts c\) 0.9 volts d\) 0.6 volts **Ans: A** 30\. In a galvanic cell, which electrode is the cathode? a\) The electrode with the higher reduction potential b\) The electrode with the lower reduction potential c\) The electrode where oxidation occurs d\) The electrode where reduction occurs **Ans: D** 31\. Which of the following statements is correct for galvanic cells written in an abbreviated form? 1. 2. 3. 4. **Ans: 4** 32\. For the redox reaction: Zn(s) + Cu2+ (0.1 M)→ Zn+ (1M) + Cu(s) taking place in a cell, E°cell is 1.10 volt. Ecell for the cell will be (2.303 RT / F = 0.0591) \(1) 2.14 V \(2) 1.80 V \(3) 1.07 V \(4) 0.82 V **Ans: 3** 33\. On the basis of following Evalues, the strongest oxidising agent is \[Fe (CN) 4 )\^ 4 --\>\[Fe(CN) 6 \]\^ 3- +e\^ - E deg = - 0.35V F e\^ 2+ → Fe\^ 3+ +e\^ - E deg = - 0.77V \(a) F e\^ 2+ \(b) F e\^ 3+ \(c) \[Fe (CN) 6 \]\^ 3- \(d) \[Fe (CN) 6 \]\^ 4 **Ans: D** 34\. In an electrolytic cell the electrode at which the electrons enter the solution is called the \_\_\_\_\_\_ ; the chemical change that occurs at this electrode is called \_\_\_\_\_\_\_. \(a) anode, oxidation \(b) anode, reduction \(c) cathode, oxidation \(d) cathode, reduction. **Ans: D** 35\. What is the purpose of the logarithmic term in the Nernst equation when applied to a galvanic cell? A\) To measure the cell's temperature B\) To adjust for pressure changes C\) To balance electron flow D\) To reflect concentration changes **Ans: D** 36\. Which of the following is the correct representation of a cell notation? a\) Cu(s) \| Cu2+(aq) \|\| Ag+(aq) \| Ag(s) b\) Ag(s) \| Ag+(aq) \|\| Cu2+(aq) \| Cu(s) c\) Cu2+(aq) \| Cu(s) \|\| Ag(s) \| Ag+(aq) d\) Ag+(aq) \| Ag(s) \|\| Cu(s) \| Cu2+(aq) **Ans: A** 37\. Ag+(aq) + e-- → Ag(s) E° = + 0.80 V Fe2+(aq)+ + 2e-- → Fe(s) E° = -- 0.44 V What is emf of Fe(s) + 2Ag+(aq) → Fe2+(aq) + 2Ag(s) \(a) 1.16 V \(b) 1.24 V \(c) 2.04 V \(d) -1.16 V **Ans: B** 38\. Given E0 \(i) Mg2+/Mg(s), E0 = -- 2.36 (ii) Ag+ /Ag(s), E0 = 0.80 \(iii) Al3+/Al(s), E0 = -- 1.66 (iv) Cu2+/Cu(s), E0 = 0.52 Out of the above-given elements which is the strongest oxidizing agent and which is the weakest oxidizing agent? \(a) (iv) is strong whereas (ii) is the weakest oxidizing agent \(b) (ii) is the strongest whereas (i) is the weakest oxidizing agent \(c) (i) is the strongest whereas (ii) is the weakest oxidizing agent \(d) (ii) is the strongest whereas (iii) is the weakest oxidizing agent **Ans: B** 39\. Which of the following factors does not affect the cell potential (Ecell) of a galvanic cell? a\) Concentration of reactants and products b\) Temperature c\) Pressure d\) Nature of the electrodes and their surfaces **Ans: D** 40\. What is the standard reduction potential of the cathode of a galvanic cell if the standard EMF of the cell and the standard reduction potential of the anode are 2.71 and -2.37 respectively? a\) 0.68 volts b\) -0.68 volts c\) -0.34 volts d\) 0.34 volts **Ans: D** 41\. E° values of some redox complexes are given below. On the basis of these values choose the correct option. E° values: Br2/Br-- = +1.90; Ag+/Ag(s) = +0.80 Cu2+/Cu(s) = +0.34; I2(s)/I-- = +0.54 V \(a) Cu will reduce Br-- \(b) Cu will reduce Ag \(c) Cu will reduce I-- \(d) Cu will reduce Br2 **Ans: B** 42\. Which of the following is true about a concentration cell? a\) The electrodes are made of different materials. b\) The cell potential is independent of the concentration of the electrolyte. c\) The cell potential is zero when the concentrations of the electrolyte are equal. d\) The cell potential is positive when the cathode concentration is higher than the anode concentration. **Ans: C** 43\. A standard hydrogen electrode has zero electrode potential because \(a) hydrogen is easiest to oxidize \(b) the electrode potential is assumed to be zero \(c) hydrogen atom has only one electron \(d) hydrogen is the lightest element **Ans: B** - 1\. Which type of coal has the highest carbon content? a\) Lignite b\) Bituminous c\) Anthracite d\) Peat **Ans: C** 2\. When 59Cu undergoes positron emission, what is the immediate nuclear product? \(a) 59Ni \(b) 58Ni \(c) 58Cu \(d) 59Zn **Ans: A** 3\. Porous materials generally (a)Transmit sound (b)Isentropic material (c)Absorb most of the sound (d)Reflect entire sound **Ans: C** 4\. Which property measures the resistance of a material to being scratched or indented? a\) Toughness b\) Hardness c\) Elasticity d\) Ductility **Ans: B** 5\. The ability of materials to develop a characteristic behavior under repeated loading known as a\) Toughness b\) Resilience c\) Hardness d\) Fatigue **Ans: D** 6\. What is the primary purpose of adding alloying elements to steel? a\) To decrease its melting point b\) To change its color c\) To improve mechanical and chem properties d\) To reduce its cost **Ans: C** 7\. Coal is classified according to \(a) its carbon content \(b) time taken in its formation \(c) layer of earth surface it is found \(d) its non carbon content **Ans: A** 8\. A radioisotope of argon, Ar, lies below the band of stability: (n/pratio too low). One would predict that it decays via \(a) neutron emission \(b) beta emission \(c) positron emission \(d) alpha emission **Ans: C** 9\. It 10% of a radioactive material decays in 5 days, then the amount of the original material left after 20 days is nearly. \(a) 60% \(c) 75% \(b) 70% \(d) 66% **Ans: D** 10\. Emission of which one of the following leaves both atomic number and mass number unchanged? \(a) positron \(b) neutron \(c) alpha particle \(d) gamma radiation **Ans: D** 11\. Straight run gasoline in the fractional column is obtained at what temperature? a\) 135°C to 170°C b\) 70° to 120°c c\) 8°C to 25°C d\) 130°C to 150°C **Ans: B** 12\. A radioactive element has half-life period of 1600 years. After 6400 years what amount will remain? Ans: (B) 1/16 13\. Where is the natural gas found? A. Inside the petroleum oil B. Inside the volcanic rocks C. Above the petroleum oil D. Below the petroleum oil **Ans: C** 14\. Which of the following products is obtained from coal tar? a\) Petrol b\) Diesel c\) Plastics d\) Wax **Ans: C** 15\. Steel balls for ball bearings are generally made A. Carbon chrome steel B. Stainless steel C. Cast steel D. Nodular cast iron **Ans: A** 16\. What is the main difference between thermosetting and thermoplastic polymers? a\) Thermosetting polymers co thermoplastics cannot b\) Thermoplastics are strong thermosettings c\) Thermosettings can be remolded upon heating, thermoplastics cannot d\) Thermoplastics can be remolded upon heating, thermosettings cannot **Ans: D** 17\. Which of the following statements is incorrect? \(a) Mass defect is the amount of matter that would be converted into energy if a nucleus were formed from initially separated protons and neutrons. \(b) Nuclear binding energy is the energy released in the formation of an atom from subatomic particles. \(c) Nuclei with highest bi are the most stable nuclei. (d).Mass number is the sum of all protons and electrons in an atom. **Ans: D** 18\. The property of a material tha absorb and dissipate energy a\) Stiffness b\) Resilience c\) Toughness d\) Malleability **Ans: C** 19\. The main alloy for corrosion resistant in stainless steel is \(A) cobalt \(B) chromium \(C) carbon \(D) manganese **Ans: B** 20\. A material\'s ability to resist wear known as: a\) Hardness b\) Toughness c\) Abrasion resistance d\) Fatigue strength **Ans: C** 21\. Which type of coal is known a\) Lignite b\) Bituminous c\) Anthracite d\) Peat **Ans: A** 22\. In order to improve machinability of steels A. Cyaniding B.Tempering C. Spheroidising D. Annealing **Ans: D** 23\. Natural gas is a ☐☐☐☐ resource \(a) non renewable \(b) living \(c) renewable \(d) all the above **Ans: A** 24\. What is the primary component of natural gas? a\) Butane b\) Propane c\) Methane d\) Ethane **Ans: C** 25\. A radioactive nucleus emits a beta The parent and daughter nuclei \(a) isotopes \(b) isotones \(c) isomers \(d) isobars **Ans: D** 26\. What is LPG mainly composed of a\) Methane b\) Propane and butane c\) Ethane d\) Hydrogen **Ans: B** 27\. Deformation that occurs due to stress over a period of time is known as a\) Wear resistance b\) Fatigue c\) Creep d\) Fracture **Ans: C** 28\. The half-life of a radioactive nucleus is 3 hours. In 9 hours, its activity will be reduced to a factor of **Ans: (D) ⅛** 29\. Which of the following attributes explain why pure metals are not frequently used in engineering applications? a\) Softness b\) Hardness c\) Brittleness d\) Luster **Ans: A** 30\. What type of ceramic material is typically used in high-temperature applications due to its thermal stability? a\) Porcelain b\) Alumina c\) Silica d\) Zirconia **Ans: B** 31\. What is the primary alloying element in brass? a\) zinc b\) Tin c\) Nickel d\) Chromium **Ans: A** 32\. What is the primary characteristic of a \'ceramic\' material? a\) High electrical conductivity b\) High thermal conductivity c\) High corrosion resistance d\) High temperature and corrosion **Ans: D** 33\. In materials science, what is \'ferromagnetism associated with? a\) Electrical resistance b\) Magnetic properties c\) Thermal conductivity d\) Optical properties **Ans: B** 34\. Which of the following is a by-product of petroleum refining? a\) Kerosene b\) Sand c\) Water d\) Salt **Ans: A** 35\. Which of the following describes what occurs in the fission process? \(a) A heavy nucleus is fragmented into lighter ones. \(b) A neutron is split into a neutron and proton. \(c) Two light nuclei are combined inte heavier one. \(d) A proton is split into three quarks **Ans: A** 36\. Which of the following describes what occurs in the fission process? \(a) A heavy nucleus is fragmented into lighter ones. \(b) A neutron is split into a neutron and proton. \(c) Two light nuclei are combined into a heavier one. \(d) A proton is split into three **Ans: A** 37\. When the number of nucleons in nuclei increases, the binding energy per nucleon numerically \(a) increases continuously with mass number. \(b) decreases continuously with mass number. \(c) First increases and then decreases with increase of mass number. \(d) Remains constant with me **Ans: C** 38\. The primary factor that determines the properties of a polymer is its: a\) Color b\) Molecular weight c\) Monomer type and arrangement d\) Melting point **Ans: C** 39\. The mass defect for an isotope was found to be 0.410 amu/atom. Calculate the binding energy in kJ/mol of atoms. (1 J = 1 kg.m²/s²) \(a) 3.69 \* 10 \^ 10 \* kJ / m \* ol \(b) 1.23 \* 10 \^ 20 \* kJ / m \* ol \(c) 3.69 \* 10 \^ 13 \* kJ / m \* ol \(d) 1.23 \* 10 \^ 3 \* kJ / m \* ol **Ans: A** 40\. Preheating of material to be welded is A. Non-ferrous materials B. Cast iron C. Stainless steel D. Carbon steel E. High speed steel **Ans: B** 41\. The term \'work hardening\' refers to: a\) Softening of metal through heating b\) Strengthening of metal through deformation c\) Weakening of metal through repo d\) Hardening of metal through a **Ans: B** 42\. Which of the following has the highest malleable A. Brass B. Cast iron C. Copper D. Lead **Ans: D** 43\. Carbon-11 is a radioactive isotope of carbon. Its half-life is 20 minutes. What fraction of the initial number of C-11 atoms in a sample will have decayed away after 80 minutes? \(a) 1/16 \(b) 1/8 \(c) 1/4 \(d) 15/16 **Ans: D** 44\. What does the term \'petroleum\' literally mean? a\) Rock gas b\) Rock oil c\) Ground oil d\) Black gold **Ans: B** 45\. Coal, Petroleum and natural gas are examples of \(a) Exhaustible Natural Resources \(b) Inexhaustible Natural Resources \(c) Expensive Resources \(d) None of the above **Ans: A** 46\. Which metal is widely used in the aerospace industry for its high strength-to-weight ratio? a\) Aluminum b\) Titanium c\) Steel d\) Copper **Ans: B** 47\. A positron has a mass number of \_\_\_\_\_ a charge of a(an) \_\_\_ and a mass equal to that of \(a) 0, 1+, proton \(b) 1, 2+, proton \(c) 0, 1+, electron \(d) 1, 2+, electron **Ans: C** 48\. What is the primary advantage of using fiber- reinforced polymers in construction? a\) Lower cost than traditional materials b\) Higher electrical conductivity c\) Improved strength and stiffness d\) Increased web **Ans: C** 49\. What is the primary principle behind fractional distillation? \(a) Solubility differences \(b) Density differences \(c) Boiling point differences \(d) Vapor pressure differences **Ans: C** 50\. The half life of 23lpa is 3.25 x 104 years. How much of an initial 10.40 microgram sample remains after 3.25 x 105 years? \(a) 0.0102 micrograms \(b) 0.240 micrograms \(c) 2.18 micrograms \(d) 0.0240 microg **Ans: A** 51\. In fractional distillation of petroleum, where do the vapours with highest boiling point condense? \(a) In the upper-most portion \(b) In the lower-most portion \(c) In the middle portion \(d) Cannot be said **Ans: B** 53\. When heated in air, coal burns to produce \(a) Carbonates \(b) Carbon dioxide gas \(c) Oxygen gas \(d) Chlorofluorocarbons **Ans: B** 54\. Which one of the following statements about nuclear reactions is false? \(a) Particles within the nucleus are involved. \(b) No new elements can be produced \(c) Rate of reaction is the independent presence of a catalyst. \(d) Rate of reaction is indepen temperature **Ans: B** 55\. The ability of a material to be formed by hammering or rolling is known as a\) Malleability b\) Ductility c\) Harness d\) Brittleness **Ans: A** 57\. Which of the following is a characteristic of brittle materials? a\) High deformation before failure b\) Low resistance to fracture c\) High energy absorption d\) Low ductility **Ans: D** 58\. Which isotope below has the highest nuclear binding energy per gram? No calculation is necessary. \(a) He \(b) 160 \(c) 325 \(d) 55Mn **Ans: D** 59\. Which one of the following would be most likely to undergo thermonuclear fusion? \(a) 2H \(b) He \(c) 50Fe \(d) Ba **Ans: A** 60\. The actual mass of a 37Cl atom is 36.966 amu. Calculate the mass defect (amu/atom) for a 37Cl atom. \(a) 0.623 amu \(b) 0.388 amu \(c) 0.263 amu \(d) 0.341 amu **Ans: D** 61\. As a result of the process of electron capture (\"K-capture\") by 2\"At, the new isotope formed is: \(a) 210 At \(b) 212At \(c) 21lpo \(d) 21Rn **Ans: C** - Which of the following processes are necessary for removing suspended solids from water? **Sedimentation** Aeration of water is done to remove **Odour** Which of the following is a method of removing temporary hardness? **Boiling** Which of these is responsible for the formation of clouds? **Transpiration** The potable water is prepared from turbid surface water by adopting which of the following treatment sequences? **Turbid surface water, coagulation, flocculation, sedimentation, filtration, disinfection, storage, and supply** The process by which plants lose water is **Transpiration** The water which had escaped from the earth as vapour returns to the earth in the form of **Precipitation** Which one of the following is the basic indicator of river health? **DO** Self-purification of natural streams is due to **All the above** Which of the following is the most impure form of natural water? **Sea water** Coagulants, used for water treatment, function better when the raw water is **Alkaline** Water can be separated from seawater through **simple distillation** Activated carbon is used in water treatment for **removing odour** In a water treatment, the optimum time of flocculation is usually given as 30 minutes. In case the time of flocculation is increased beyond this value, the flocs will **Become heavy and settle down the flocculation tank itself** Treatment required for raw water containing only carbon dioxide and odorous gases is **Aeration followed by disinfection** The process of conversion of water into vapours is called **Evaporation** The various treatment processes in a water treatment plant are listed below I. Filtration II\. Chlorination III\. Sedimentation IV\. Coagulation V. Flocculation **iv, v, iii, i, ii** When alum is added to the waste water containing calcium ions which compound is formed as a precipitate? **Al(OH)3** Which of the following is the product obtained when a coagulant is mixed with waste water? **sediments** The water treatment required for water obtained from a deep tube well is **Disinfection only** In how many states of matter does water exist? **Three** Chlorides are normally present in water in the form of **Sodium chloride** In the concept of self purification of natural streams, complete the following phrase. Solution to pollution is **Dilution** **0** D.O. concentration may fall to zero, causing anaerobic conditions in a river reach is called **zone of active decomposition** In which of the following does condensation of water vapour take place? A. Breathing on to a mirror B. Heating an open beaker in water C. Leaving a glass of ice on the table D. Leaving a cup of water by the window **A and C** The disinfection efficiency of chlorine in water treatment **is reduced by increased pH value** Which of the following treatments is the most economically effective method for controlling Schistosomiasis? **Chlorination** A river is the source of water supply to a town. Its water is very turbid and polluted. The correct sequence of steps for treating the river water would be **presedimentation → prechlorination → coagulation → sedimentation → filtration → post chlorination** Matching Type Boiling - **E. Heating water @ 100°C for 10-20 mins** Filtration - **D. Using sand, charcoal or ceramic** Distillation **- C. Condensing steam** UV Treatment **- B. Uses light to damage DNA of pathogens** Reverse Osmosis **- A. Uses semi-permeable membrane under pressure** Sludge **- F. Product of sedimentation** Alum **- G. Coagulant** - - a\) ABAB b\) AABB c\) ABCABC d\) AAA **Ans: D** - a\) Copper b\) Potassium c\) Chromium d\) Polonium **Ans: A** - a\) Highest packing efficiency b\) Highest void fraction c\) Highest density d\) All of the mentioned **Ans: A** - **Ans: A** - **Ans: A** - a\) 6 b\) 12 c\) 8 d\) 4 **Ans: C** - a\) FCC b\) BCC c\) HCP d\) TCP **Ans: A** - a\) Li, Na, K b\) Be, Zn, Cd c\) Li, Al, Ca d\) As, Cr, Bi **Ans: A** - a\) False b\) True **Ans: True** - a\) 308°C b\) 568°C c\) 771°C d\) 906°C **Ans: D** - \(a) Crystal \(b) Lattice \(c) Unit cell \(d) Miller indices **Ans: C** - \(a) Distance between two adjacent atoms \(b) Projected area fraction of atoms on a plane \(c) Volume fraction of atoms in cell \(d) None **Ans: C** - a\) W b\) Mo c\) Cr d\) Zr **Ans: D** - a\) 6 b\) 8 c\) 10 d\) 12 **Ans: A** - a\) BCC \< Simple cubic \< CCP b\) HCP \