ECAT Chemistry MCQ's Test For Full Book With Answers

ECAT Chemistry MCQ's Test For Full Book

Sr. # Questions Answers Choice
1 Buffers having pH less than 7 are made Mixture of weak acid + salt of it with strong base Mixture of weak acid + salt of it with weak base Mixture of weak base + salt of it with strong acid Mixture of weak base + salt of it with weak base
2 The relation between Kc and Kp is
3 pH of the human blood which is essentially maintained constant due to carbonates, biocarbonates, phosphates etc., is 7.00 7.25 7.35 7.47
4 A buffer solution of 0.1 molar HCOOH and 0.1 molar HCCONa has pH = 3.78 To is 0.01 molar HCl is added, then pH of the buffer solution becomes 2.78 4.78 3.78 3.70
5 If pH of buffer of 1 mole dm-3of HCOOH + 0.1 mole dm-3HCOONa having pKa = 3.78 is 1.78 2.78 3.78 4.78
6 pH of 0.1 molar HCl solution is 1 zero 13 14
7 A buffer of a 0.09 molar acetic acid and 0.11 molar sodium acetate has pH = 4.83. If 0.01 mole NaOH in 1 dm3of the buffer solution is added, then pH of the buffer becomes 4.74 4.92 5.0 4.0
8 pH of water is 7, if 0.01 M NaOH is added, than its pH is 12 14 zero 10
9 pH of 1 molar NaOH is 7 zero 14 10
10 pKb value of NH4OH is 4.74. If the concentration of NH4OH is 1 molar containing 0.1 molar NH4Cl, then pH of this buffer will be 3.74 10.26 4.74 9.26
11 ph of the buffer CH3COOh + CH3COONa is 3.76. If the mixture contains 1 molar acetic acid and 0.1 molar sodium acetate, then pKa of this buffer is 3.76 4.76 5.76 6.76
12 The best buffer is prepared when molar concentrations of the salt and acid are equal, then its pH and pKa value are related pH = pKa pH < pKa pH > pKa pH x pKa = 14
13 pH and pKa of the buffer are related by Henderson equation which is
14 Kbvalue of NH4OH is 1.81 x 10-5and its conjugate acid has Ka= 5.7 x 10-10pKb of the base is 4.74, pKa of its conjugate acid is -4.74 4.74 10 9.26
15 strength of an acid can be determined by P<sup>ka</sup> P<sup>kp</sup> P<sup>oH</sup> P<sup>kw</sup>
16 When fused PbBr2is electrolyed then Bromine appears at cathode Lead deposited at the cathode Lead appears at the anode None of these happens
17 An electrochemical cell is based upon Acid-base reaction Redox reaction Nuclear reaction None of the above
18 Sodium metal is obtained by the electrolysis of fused NaCl in cell is called Nelson's cell Down's cell Daniell cell Voltaic cell
19 -1.10 V +1.10 V -0.42 V +0.42 V
20 Iodine can oxidise iron Bromine can oxidise iron Iodine can oxidise bromine Iron can oxidise bromine
21 A strong reducing agent A strong oxidising agent Better oxidising agent than hydrogen Less reducing agent than hydrogen
22 A standard hydrogen electrode (S.H.E) consists of a platinized platinum electrode dipped in 1 molar solution of H+ions and hydrogen gas is passed at a pressure of One pascal One kilo pascal One atmoshpere Then atmoshpere
23 Adding H<sub>2</sub>O and H<sup>+</sup>ions Adding OH<sup>-</sup>ions Adding O<sup>2</sup>molecules Adding O atoms
24 Corrosion reaction are Spontaneous redox reaction Non-spontaneous acid-base reactions Spontaneous acid-base reactions None of these
25 Standard reduction of Zn = -0.76 V and that of Ni is -0.25 V. On coupling them by a salt bridge which of these will act as anode Salt bridge will act as anode Zn will act as anode Ni will act as anode None of these
26 Zn does not displace Mg from MgSO4solution because Zn is more electropositive than Mg Zn is below Mg in electropositive series Zn is above Mg in electrochemical series Zn is trivalent Mg is divalent
27 Fe can displace Cu form CuSO4solution because Fe is ferromagnetic Fe is below Cu in electrochemical series Fe is above Cu in electrochemical series Fe exists in divalent oxidation state
28 Which of the following will be good conductor of electricity Pure distilled water Molten NaCl Dilute solution of glucose Chloroform
29 In KO2the oxidation state of oxygen is -2 -1 +1/2 -1/2
30 F2, Cl2, Br2and l2lie below SHE is the Electro chemical series that is why these Undergo reduction Undergo oxidation Liberate H<sub>2</sub>gas with steam None of these
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