AP Chemistry Model Question Paper

1.	The d-electron configurations of Cr2+, Mn2+, Fe2+ and Co2+ are d4, d5, d6 and d7 respectively. Which one of the following will exhibit minimum paramagnetic behaviour? (A) [Cr(H2O)6]2+ (B) [Mn(H2O)6]2+ (C) [Fe(H2O)6]2+ (D) [Co(H2O)6]2+ (At. nos. Cr = 24, Mn = 25, Fe = 26, Co = 27)	Answer: (D)
2.	The electrode potentials for and are + 0.15 V and + 0.50 V respectively. The value of   will be (A) 0.150 V (B) 0.500 V (C) 0.325 V (D) 0.650 V	Answer: (C)
3.	The electronic configuration of Cr3+ is (A) [Ar]3d54s1 (B) [Ar]3d24s1 (C) [Ar]3d34s0 (D) [Ar]3d44s2	Answer: (C)
4.	The electrophile involved in the sulphonation of Benzene is (A) (B) so3 (C) (D)	Answer: (B)
5.	The empirical formula of a nonelectrolyte is C1H2O1. A solution containing 6 g of the compound exerts the same osmotic pressure as that of 0.05 M glucose solution at the same temperature. The molecular formula of the compound is ______. (A) C3H6O3 (B) C2H4O2 (C) C4H8O4 (D) C5H10O5	Answer: (C)
6.	The energies E1 and E2 of two radiations are 25 eV and 50 eV respectively. The relation between their wavelengths i.e. and will be (A) = (B) = (C) = 2 (D) = 4	Answer: (C)
7.	The enthalpy of formation of NH3 is -46 kJ mo1-1. The enthalpy change for the reaction : 2NH3(g) ® N2(g) + 3H2(g) is (A) +92kJ (B) +46 kJ (C) +184 kJ (D) +23 kJ	Answer: (A)
8.	The following data is obtained during the first order thermal decomposition of 2A(g) B(g) + C(s) , at constant volume and temperature.  Sr. No.  Time                                    Total pressure in Pascal 1           At the end of 10 minutes 300   300 2           After completion 200              200 The rate constant in min-1 is ______. (A) 6.93 (B) 0.0693 (C) 69.3 (D) 0.00693	Answer: (B)
9.	The freezing point depression constant for water is –1.86°Cm–1. If 5.00 g Na2SO4 is dissolved in 45.0 g H2O, the freezing point is changed by -3.82°C. Calculate the van't Hoff factor for Na2SO4 (A) 0.381 (B) 2.05 (C) 2.63 (D) 3.11	Answer: (C)
10.	The function of Fe(OH)3 in the contact process is (A) to remove moisture (B) to remove dust particles (C) to remove arsenic impurity (D) to detect colloidal impurity	Answer: (C)