PPSC Chemistry Full Book Test With Answers

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PPSC Chemistry Full Book Test

Sr. # Questions Answers Choice
1 Which of the following is not a property of aluminium. An efficient electrical conductor A low density compared to other metals Is amphoteric Toxic to humans
2 Aluminum is an active metal but does not corrode as iron does because. Ai does not react with O2 A protective layer of Al2 O3 forms on the metal surface AI is harder to Oxidize than is Fe Aluminium has a high tensile strength
3 The Hall process involves the reduction of Al2O3 to aluminium by Carbon Carbon monoxide Molecular hydrogen Electrolysis
4 The role of the mineral cryolite Na2AlF6 in the Hall process for aluminum production is. It is the source of aluminum it is a chemical reducing agent It forms a slag to remove impuriteis In the molten state, it is a solvent for alumina Al2O3
5 Which of the following statement is incorrect. An alloy is a mixture of two or more metals An alloy is a mixture of two or more metal and non metal elements that have metallic properties An alloy has a fixed composition An amalgam is an alloy containing Hg
6 Aluminium does not corrode as does iron because. AI does not react with O2 a-protective layer of Al2O3 forms on the metal surface AI is harder to oxidize than is Fe Fe gives chathodic protection to AI
7 The element with maximum first ionization energy is. B N O C
8 The most abundant metal in earth's crust is. Fe Al Ti Ca
9 Which of the group 13 element does not form M (III) idodie. Al Ga Ti In
10 In B2H6 molecule There exists a direct B-B a -bond All the atoms are in one plane All the B-H bonds are normal covalent bonds There exist two bonds between the boron atoms.
11 The aluminium salt commonly used to stop bleeding is Aluminium sulphate Potash Alum Aluminium chloride Aluminium fluroide
12 Which librates H2 with NaOH B AI Zn All
13 Which one of the following statements regarding BF3 is not correct. It is an ionic compound It is an electron deficient compound It is a Lewis acid <div>It forms adducts</div>
14 Anhydrous AlCl3 cannot be obtained by heating hydrated AlOI3 ,6h2o Because. It decomposes completely to give Al2O3 It does not lose water completely It undergoes hydrolysis to give Al(OH)3 AlCl3 .6H2O is very stable.
15 Which of the following statements is not true about potash alum. Its empirical formula is KAI (SO4)2 12H2O Its aqueous solution is basic in nature It is used in dyeing industry On heating it melts in its water of crystallization
16 When orthoboric acid is heated strongly it gives. B2O3 H2B3O7 HBO2 B
17 When borax is strongly hented, it gives B2O4 Na2B4O7 NaBO2 NaBO2 + B2O3
18 In the Aluminothermite process, aluminium acts as. An oxidizing agent A reducing agent A flux A Solder
19 In the electrolysis of alumina, cryolite is added to. Lower the melting point of alumina Increase the electric la conductivity Minize anodize affect Remove impurites from alumina
20 The major role of Flurospar which is added in small quantities in the electrolytic reduction alumina dissolved in fused cryolite is. As a catalyst To make the fused mixture very conducting To lower the temperature of the melt To decreases the rate of oxidation of carbon at the anode
21 Hydrogen gas will not redue Heated cupric oxide Headed ferric oxide Heated stannic oxide Heated aluminium oxide
22 Concentrated aqueous sodium hydroxide can separate a mixture of. Al3+ and Sn2+ Al3+ and Fe3+ Al3+ and Zn2+ Zn2+ and Pb2+
23 Amorphous boron on burning in air form B(OH)3 Only B2O3 Only BN Mixture of B2O3 and BN
24 Which of the following statements is not true for both B and Al They burn in oxygen to give oxides at high temperature Their halides are Lewis acids They combine with nitrogen to form nitrides They react with HCl to form chlroides.
25 Which of the following statements about anhydrous aluminium chloride is correct. It exist as AlCl3 molecules It is not easily hydrolysed It sublimes at 100 <sup>o</sup>C under vacuum Boron does not form B<sup>3+</sup> ions
26 AlCl3 fumes in air because of. Hydrolysis Dehydration Hydration Oxidation
27 Inert pair effect is that When an element shows incertness in chemical combination When higher oxidation state is more stable than lower oxidation state When an elecrron pair is present on the atom of an element When two s -electrons or outermost shell remain paired and do not participate in bonding.
28 Boron does not form B3+ ion because. It has small size and high ionization energy It has high electromagnetically It has high charge density None of the above
29 Alums are generally used In Dying and water proofing of fabric In arrest bleeding IN water purification All above
30 LiAIH4 is most useful reducing agent It reduce to alcohol Aldehydes Ketone Carboxylic acid Any of above
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