Which of the following elements is the most electropositive? a) B b) C c) Cl d) N
Which species does not contain an sp3-hybridized atom? a) BH3 a) NH4+ b) NH3 c) none of these d) BH3
Photochemical smog normally does not contain? a) Chlorofluorocarbons b) Peroxyacetyl nitrate c) Ozone d) Acrolein
Which of the following molecules does not have a dipole moment? (PPSC 2015)? a) CCl4 b) CH2Cl2 c) CHCl3 d) CH3Cl
The coldest region of the atmosphere (PPSC 2017)? a) Mesosphere b) Stratosphere c) Troposphere d) Thermosphere
Regular use of which of the following fertilizers increases the acidity of soil? a) Potassium nitrate b) Superphosphate of lime c) Ammonium sulphate d) Urea
Find the incorrect statement? a) BOD value of clean water is less than 5 ppm b) Drinking water pH should be between 5.5-9.5 c) carbon, sulphur and nitrogen oxides are the most widespread air pollutants d) dissolved oxygen concentration below 5 ppm is ideal for the growth of fish
Which of the species is not paramagnetic? a) As+ b) Cl– c) Ne2+ d) Be+
C-O bond length is minimum in? a) CO2 b) CO32- c) CO d) all has same
Which of the following reactions may be associated with aldehyde and ketone? (PPSC 2021)? a) Nucleophile addition b) Polymerization c) Oxidation d) All of the above
Sp3d2 hybridization is present in [Co(NH3)63+], find its geometry (PPSC 2020)? a) octahedral geometry b) square planar geometry c) tetragonal geometry d) tetrahedral geometry
For the same value of n, the penetration power of orbital follows the order? a) s = p = d = f b) p > s > d > f c) f < d < p < s d) s < p < d < f
Which of the following statements is incorrect? a) I.E.1 of O is lower than that of N but I.E.2 O is higher than that of N b) Isoelectronic ions belong to the same period c) The enthalpy of N to gain an electron is almost zero but of P is 74.3 kJ mol-1 d) none of these
Which one will have the highest 2nd ionization energy? a) 1s2 2s2 2p4 b) 1s2 2s2 2p6 3s1 c) 1s2 2s2 2p6 d) 1s2 2s2 2p6 3s2
Gluconeogenesis involves the______. (PPSC 2021)? a) synthesis of glycogen from glucose b) breakdown of glycogen to form glucose c) breakdown of glucose to produce pyruvate d) None of the these
Which of the following disaccharides gives two same monosaccharide units on hydrolysis? (PPSC 2021)? a) Maltose b) Sucrose c) Lactose d) none of these
Which of the following substance produce acetaldehyde on dry distillation? a) (CH3COO)2Ca b) (HCOO)2Ca c) None of these d) Both A and B
Which of the following substances does not give iodoform test? (PPSC-2017)? a) Acetaldehyde b) Ethyl alcohol c) Acetone d) Methyl alcohol
Which of the following compounds will react with Tollen’s reagent? a) CH3-CHO b) CH3-CH-CH3 c) CH3-COOH d) CH3-CO-CH2-CH3
In which of the following methods are liquid samples injected into the column in gas chromatography? (PPSC 2021)? a) Gas tight syringe b) Micro-syringe c) Rotary sample valve d) None of these
