Chemistry Mcqs For CSS & PSC Exams
(i) The geometry associated with sp3d 2 hybridization is:
(a) Octahedral (b) Tetrahedral (c) Trigonal planar (d) Trigonal biplanar
(ii) Which of the following molecules has a dipole movement?
(a) CH4 (b) CO2 (c) H2 O (d) CCl 4
(iii) Which of the following represents the shape of NH 3 molecule?
(a) Trigonal planar (b) Angular (c) Trigonal Pyramidal (d) Tetrahedral
(iv) Which of the following is the largest ion?
(a) Li (b) Cs (c) Rb (d) Na
(v) Which of the following represent different isotopes of the same element?
1. 12 protons, 11 neutrons, 12 electrons
2. 11 protons, 12 neutrons, 11 electrons
3. 10 protons, 12 neutrons, 12 electrons
4. 11 protons, 12 neutrons, 10 electrons
5. 12 protons, 12 neutrons, 12 electrons
(a) 1 and 5 (b) 2 and 4 (c) 2, 3, 4 and 5 (d) None of these
(vi) Which of the following represents the correct number of particles in 79 2
34 Se ?
(a) 34 protons, 79 neutrons, 2 electrons (b) 34 protons, 45 neutrons, 32 electrons
(c) 34 protons, 45 neutrons, 2 electrons (d) 34 protons, 45 neutrons, 36 electrons
(vii) Which one of the following is correct equation for the reaction of chlorine with water?
2Cl + H 2 O2HCl +
(b) Cl 2 + 2H 2 O 2HCl + H 2 O2
(c) Cl 2 + 3H 2 OHClO3 + 5HCl (d) Cl 2 + H 2 O HCl + HOCl
(ix) When Pt and Co are electrically connected, which one is corroded:
(a) Pt (b) Co (c) Both of these (d) None of these
(x) For the reaction (Zn + Cu 2 Zn 2 +Cu), which of the following statements is correct?
(a) Zn is dissolved and Cu is deposited (b) Cu is reduced and Zn is exidized
(c) Cu is the cathode and Zn the anode (d) All statements are correct
(xi) What is the pH of 0.0001 M NaOH solution?
(a) 4 (b) 10 (c) 5 (d) 14
(xii) What is the pH of 1.0 x 10 3M HCl solution?
(a) 10 (b) 30 (c) 3 (d) 0.3
(xiii) Which of the following is the correct equilibrium expression for the reaction
[N 2 (g) + 3H 2(g) 2 ( )] 3 NH g ?
(a) [ 3 2NH ][N 2 + 3H 2 ] (b) [2NH 3 ] / [N 2 ][3H 2 ]
(c) [NH 3 ] 2 / [N 2 ][H 2 ] 3 (d) [NH 3 ] 2 / [N 2 ]+[H 2 ] 3
(xiv) Which of the following best describes how a catalyst works?
(a) It changes the potential energies of the reactants and products.
(b) It decreases the temperature of the reaction which leads to a faster rate.
(c) It lowers the activation energy for the reaction by providing a different reaction mechanism.
(d) It raises the activation energy for the reaction which produces a faster rate.
(xv) Which of the following will not act as Lewis acid;
(a) AlCl 3
(c) FeBr 3
(d) CCl 4
(xvi) Which of the following is the strongest acid?
(a) HF (b) HCl (c) HBr (d) HI
(xvii) Which of the following could be used for cathodic protection:
(a) Al (b) Cd (c) Cu (d) None of these
(xviii) Hybridization of XeF 4 is:
(a) sp 3 d (b) sp 2 d 2 (c) sp 3 d 2 (d) sp 3
(xix) Which of the following will increase the rate of the reaction?
(a) Decreased temperature and increased concentration of reactants
(b) Decreased temperature and decreased concentration of reactants
(c) Increased temperature and decreased concentration of reactants
(d) Increased temperature and increased concentration of reactants
(xx) Silicones are polymeric substances with linkage:
(a) Si – S – Si (b) Si – O – Si (c) Si (CH 3 ) 4
(d) O = Si = O