PPSC Chemistry Full Book Test With Answers

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PPSC Chemistry Full Book Test

Sr. # Questions Answers Choice
1 Identify the incorrect statement regarding crystallization from the following. It is an important procedure for purifying solids The impurities are removed by filtering the solution Crystals are separated by filtration In crystallization method, the solid is dissolved in a solvvent in which it is soluble at all temperature.
2 An impure sample of camphor contaminated with sand, can be purified by Distillation Sublimation Steam distillation None of the above
3 Sugar and common salt in a mixture can be separated through then process of. Sublimation Distillation Ion exchange Crystallization from solution in ethanol
4 Recrystallization is the most common technique of purification of solid organic substances Which of the following statements is not related with characteristics of a suitable solvent. It dissolves the substance on heating It readily allows it to separate out in the form of crystal on cooling It does not react chemically with substance It does dissolve the impurities.
5 Which of the following techniques is involved in purification of organic compound. Distillation Sublimation Solvent extraction All above
6 When of the following steps is involved in structure determination of an organic compound. Purification of compund. Qualitative and quantitative analysis of elements present Determination of molar mass All above steps
7 Which of the following compounds has highest dipole moment. Dichloromethane Chloroform Chloromathane All above
8 The most stable carbonium ion is See butyl n-butyl Tert butyl None of the above
9 Which of the following statement is false about resonance. It increase the stability of a molecule It leads to similar type of bonds It increase the reactivity of the molecule It decrease the reactivity of the molecule.
10 Which statement is true. Resonance hybride are inherently unstable. Resonance hybride are more static than any individual resonance form Resonance hybride are average of all resoance forms resembling the more stabel forms None of the above
11 The bond length of C = C is 1.20 A<sup>o</sup> 1.34 A<sup>o</sup> 1.54 A<sup>o</sup> 1.68 A<sup>o</sup>
12 The bond angle between hybrid orbitals in methane is 115.5<sup>o</sup> 109.5<sup>o</sup> 105,7<sup>o</sup> 120<sup>o</sup>
13 Which of the following is a planar molecule. Acetone Formic acid Acetic acid All above
14 The greater stability of bonzyl carbonium ion as compared to t-butyl carbonium ion is due to. Inductive effect Resonance effect Electrometric effect All above
15 All bond length in benzene are identical due to. Resonance effect Inductomeric effect Electromeric effect Mesomeric effect
16 Trimethylamine is a weaker base than dimethylamine is explained by Steric effct Resonance effect Inductive effect All above
17 Which of the following effects best explains that o-nitro phenol is insoluble in water. Inductive effect Resonance effect Intramolecular H -bonding Isomeric effect
18 Which of the following is most acidic. Phenol p-nitrophenol o-Nitrophenol m-Nitrophenol
19 Which of the following is most basic. Aniline Benzylamine Diphenylamine N-methylaniline
20 Which of the following group will have hyper conjugation effect when attached to benzene. ------ CH3 ----C6H5 ------C(CH3)3 ---------CH(CH3)2
21 Chlorine when attached to benzene has +1 and + R effect -1 and - R effect -1 and +R effect None of the above
22 C - O bond lengths in carboxylate anion are equal due to. Resonance effect Inductive effect Resonance of identical contributing structures. Hyperconjugation
23 The criteria for aromatically is presence of Uneaturations Cyclic structure Presence of 4nx electrons Presence of 4n + 2n electrons
24 The denationalization involving C - H sigma bond electrons is known as . Conjugation Hyperconjugation Mesomerism Resonance
25 Compounds consisting of two or more interlocked rings are called. Inclusion compounds Cage compounds Catenanes Crown other
26 Cyclic polymers of ethylene glycol formed by condensation are called. Crown ether Brown ether Cryptates Both A and C
27 The common host compound for the formation of inclusion compound is. Urea Thiourea Cholic acid All above
28 The compounds whose formation require a host compound and a guest compound are called. Exclusion compounds Inclusion compounds Crystal compounds None of the above
29 Which of the following statements is not correct with respect to applications of H- bonding. It explains the usual b.p. and m.p of certain class of compound. It explains the solubility of certain organic compounds in hydroxylic solvents It explains the lack of ideal behavior in gases and solutions It has stonrg influence on the configuration of certain molecules.
30 In hydrogen bonding a hydrogen atom is bonded to which of the highly electronegative atoms. N O F N,O,F
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