MDCAT Chemistry Online Test With Answers

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MDCAT Chemistry Online Test

Sr. # Questions Answers Choice
1 Coinage metals Cu. Ag, and Au are the least reactive because they have Negative reduction potential Positive reduction potential Negative oxidation potential Positive oxidation potential
2 Only those metals can replace Hydrogen from dilute acids, which have High negative reduction potential Low negative reduction potential High positive reduction potential low positive reduction potential
3 Which one of the following metals can replace the Copper from aqueous solution of its salt more easily? Cd Fe Zn Na
4 The standard reduction potential of Zinc is 0.76V 0.34 -0.34V -0.76V
5 When a metal rod is dipped in its one molar ionie solution Electricity is produced Electricity is consumed Redox reaction occurs Potential difference is set up
6 On ascending the electrochemical series strength as reducing agent Increases Decreases Remains same not determinable
7 The potential difference set up at 25 C and 1 atm when clectrode is dipped m Tis one molar ionic sohution is called Single electrode potential electrode potential Standard electrode potential Standard hydrogen electrode
8 The cell which converts electrical energy to chemical energy is called Electrochemical cell Voltaic cell Galvanic cell Down's cell
9 Molten lead and iead (II) bromide both conduct electricity. Which one of the following statements relating to this is true? Both undergo chemical change when they conduct Both conduct by the movement of charge particles Both will also conduct in the solid state Both contain mobile electrons
10 Zinc reacts with dilute acids to liberate hydrogen. This is because: Zn2+ ion is a powertul osidising agent than H' ion H+ ion is a powerful oxidising agent than Zn ion Zn2+ ion is a powerful reducing agent than H' ion H+' ion is a powerful reducing agent than Zn- ian
11 Which of the following salts would give the same products irrespective of whether its molten form or concentrated aqueous solution is electrolysed? Magnesium bromide Magnesium sulphate Copper sulphate Copper chloride
12 Electrolytic products of dilute aqueous solution of sodium sulphate is Na. SO2 H2. S02 Na. O2 H2,O2
13 Which of the following is an application of electrochemical series Prediction of the feasibility of chemical reaction Calculation of the cell voltage Prediction of reaction of metal with dilute acid All of the above
14 If a strip of Cu metal is placed in a solution of FeSO4 Cu will be deposited Cu and Fe both dissolve Fe is precipitated out No reaction take place
15 Which of the following statements is not correct about galvanic cell? Anode is negatively charged Cathode is positively charged Reduction occurs at anode Reduction occurs at cathode
16 By the electrolysis of CuCl2 using inert electrodes of platinum which species is deposited at cathode H2 O2 Cu CI
17 The reduction potentials of non-metals are A =+0.54V, B=+1.08V, C=+1.36V. D= +2.87V Which non -metal can displace all other from aqucous solution of their salts A C B D
18 Which of following is oxidation state of oxygen in peroxides? -2 1/2 -1 +2
19 Stronger the oxidizing agent, higher is Redox potential Standard reduction potential Reduction potential <sub>Oxidation potemial</sub>
20 The emf produced by galvanic cell is called Cell potential Oxidation potential Redox potential Reduction potential
21 If Cl2 is passed through hot NaOH. NaCIO3 is formed and the oxidation number of CI changes from -1 to 0 0 to +5 0 to-1 0 to +1
22 The element which has greatest value of Reduction potential is used as Strongest reducing agent Weak oxidizing and strong reducing agent Strongest oxidizing agent None of these
23 A system absorbs 100 kJ heat and performs 50 kJ work on the surroundings. The increase in internal energy of the system is 50kJ 100 kJ 150kJ 5000 kJ
24 The enthalpy change AH of a process is given by the relation ΔΗ =ΔΕ + P∆V ΔH=ΔE +W ΔH =ΔΕ-ΔnRT ΔΕ =ΔΗ + P∆V
25 ΔH° represent the enthalpy change at 0°C and 1 atm pressure 25°Cand 1atm 0K and I atm pressure 25°C and 2 atm pressure
26 Born-Haber cycle is an application of Hess's law 1" law of thermodynamics Avogadro's law 1law of thermochemistry
27 Neutralization of acid-base is Spontaneous Exothermic Non spontaneous Both "a" and "c
28 The change in enthalpy when one mole of a substance is dissolved in a specified quantity of solvent at a given temperature is called Heat of reaction Heat of solvation Heat of combustion Heat of solvent
29 Which of the following enthalpy change always have a negative value ∆Hf ∆H sol ∆Hc ∆Hat
30 The change in enthalpy of a system when one mole of the substance is completely burnt in excess of air or oxygen is called Heat of reaction Heat of formation Heat of atomization Heat of combustion
31
By convention, the standard heat of formation of all elements is assumed to be
 Zero positive Negative Infinity
32 One kilo calorie is equal to 4.184J 1000J 4184J 1kJ
33 ∆H=∆E is true for which of the following reaction K+H2O-----&gt;KOH+H2 N2+3H2------&gt;2NH3 AlCl3+3NaOH---&gt;Al(OH)3+3 NaCl 4Na + O2-----&gt;2Na2O
34 Which of the following processes has always. ∆H=-ve Formation of compound Dilution of a solution Dissolution of ionic compound Combustion
35 Enthalpy of a system can be calculated by which of following relationship q=ΔΕ q=m×S×∆T q=pv q=m×v×∆T
36 One of the best applications of Hess's law to calculate the lattice energy of ionic compound is Measurement of enthalpy change in a calorimeter Studying of first law of thermodynamics Measurement of a heat of formation of a compound Born-Haber cycle
37 How much heat is absorbed by 100 g of water when its temperature decreases from 25°C to 5°C? (heat capacity is 4.2 J/gK) 84,000J 2000/4.2J -2000/4.2j -8400J
38 Whenever a reaction is endothermic, then it means that Heat is transferred system to the surrounding Heat is transferred from surrounding to the system Heat content of the products is less than that of reactants Heat content of the reactants is greater than the products
39 Enthalpy of neutralization (∆H°n) per mole of H2SO4/ Ba(OH)2 is +57.4 kJmol-1 -114.8 kJmol-1 -57.4 kJmol-1 -57.4 kJmol-1
40 In order to determine ∆H (latt) of ionic compound which is correct relationship ∆H latt. = ∆Hf - ∆Hx ∆H latt. = ∆Ha + ∆Hv ∆H latt. = ∆Hf + ∆Hx ∆H latt. = ∆Hf - ∆H sol.
41 Enthalpy of a reaction can be measured by Glass calorimeter Barometer Manometer Thermometer
42 If internal energy of the system is increased Change in state of the system may occur Temperature of the system may rise Chemical reaction may take place All of these
43 Change in enthalpy (∆H) of a system can be calculated by ∆H=∆E - PV ΔH =ΔE +q ∆H = ∆E - q ∆Η = ΔΕ + P∆V
44 Choose from the followings the correct statement about Born Haber cycle Born Haber cycle is different from Hess's law The energy changes in a cyclic process is not zero The lattice energy of crystalline substances can be calculated easily None
45 Enthalpy of formation of one mole of ionic compound form gaseous ion under standard condition is called Gibb's energy Gibb's energy Bond energy Lattice energy
46 According to Hess's law, the enthalpy change for a reaction Depends on path Independent of the path The sum of ∆E and ∆H None of these
47 Decomposition of H2O is Endothermic reaction Nuclear reaction Exothermic reaction Zero nuclear reaction
48 The lattice energy of NaCl is 787 j/ mole 790 kj/mol 780 kJ/ mol -787 kI / mole
49 The value of ∆V being very small. The term P∆V can be neglected for process involving Liquid and gas Solids and gases Liquid and solid None of these
50 The enthalpy change for the reaction C2H2 + 5/2 O2 --------> 2CO2 + H2O is known as enthalpy of Fomation of CO2 Fusion ofC2H4 Combustion of C2H4 Vaporization of C2H2
51 A state function which describes together the internal energy and product of pressure and volume is called Enthalpy internal energy Work Kinetic energy
52 The enthalpies of all elements in their standard states are Unity always +ve always -ve zero
53 Total heat content of a system is called Internal energy Entropy Enthalpy All of these
54 The measurement of enthalpy change at standard conditions means that we should manage the measurement at 24°C at 1 atm 25°C at 1 atm 0C° at 1 atm 100C° 1 atm
55 Most of the reactions which give stable products are Endothermic Exothermic Isothermal Non of these
56 During an exothermic or endothermic reaction which one of the following formula is used to calculate the amount of heat evolved or absorbed ΔΗ = ΔΕ+PV ∆E= q+w Δp =ΔΗ q = m x s x ∆T
57 The exothermic process is Evaporation Sublimation Respiration Boiling
58 The heat of reaction depends upon Temperature of the reactants Physical states of the reactants and the products Both A) and B) Path of the reaction and the temperature
59 One Joule is equivalent to 4.184 cal. 0.4184cal. 1/2 cal. 1/4.184 cal
60 If an endothermic reaction is allowed to take place very rapidly in air, the temperature of the surrounding air will Remains constant Increase Decrease Either increase or decrease One Joule is equivalent to
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