1. When H2S is passed through Hg2S, we get(2002)
(1)HgS 2) HgS + Hg2S
3) Hg2S 4) Hg2S2
Ans.
2. Alum helps in purifying water (2002)
(1)forming Si complex with clay particles
(2) sulphate part, which combines with the dirt and removes it
(3)coagulating the mud particles
(4)making mud water soluble
Ans. (3) Alum furnished Al3+ ions which bring about coagulation of negatively charged clay particles, bacteria, etc.
3. In the case of nitrogen, NC13 is possible but not NC1S, while in the case of phosphorous, PC13 and PC15 are possible. It is due to the (2002)
(1)availability of vacant d orbitals in P but not in N
(2)lower electronegativity of P than N
(3)lower tendency of H-bond formation in P than in N
(4)occurrence of P in solid while N in a gaseous state at room temperature
Ans.(1) 7N2 =ls22s23p3, 15P = 1 s22s22p63s23p3 In phosphorous the 3d – orbitals are available
4. Number of sigma bonds in P4O10 is (2003)
(1)6 2) 1 3) 17 4) 16 Ans.
Ans.
5. What happens when phosphine gas is mixed with chlorine gas? (2003)
(1)PC13 and HC1 are formed, and the mixture warms up
(2)PC15 and HC1 are formed, and the mixture cools down
(3)PH3.C12 is formed with warming up
(4)The mixture only cools down
Ans.
6. Graphite is a soft solid lubricant extremely difficult to melt. The reason for this anomalous behavior is that graphite. (2003)
(1)is an alio tropic form of diamond
(2)has molecules of variable molecular masses like polymers
(3)has carbon atoms arranged in large plates of rings of strongly bound carbon atoms with weak interplate bonds.
(4)is a non-crystalline substance.
Ans.(1) 4HC/ + 02–> 2Cl2 + 2H20 cloud of white fumes.
7. Concentrated hydrochloric acid, when kept in the open air, sometimes produces a cloud of white fumes. The explanation for it is that (2003)
(1)oxygen in the air reacts with the emitted HC1 gas to form a cloud of chlorine gas
(2) The strong affinity of HC1 gas for moisture in air results in the formation of droplets of a liquid solution, which appears like a cloudy smoke.
(3)due to a strong affinity for water. Concentrated hydrochloric acid pulls moisture of air towards itself. This moisture forms droplets of water and hence the cloud.
(4)concentrated hydrochloric acid emits strongly smelling HC1 gas.
Ans. (3) Layers are held together.
8. Glass is a (2003)
(1) super-cooled liquid 2) gel
(3)polymeric mixture
(4)micro-crystalline solid
Ans. (1) Glass is a transparent or translucent supercooled liquid.
9. For making good quality mirrors, float glass plates are used. These are obtained by floating molten glass over a liquid metal that does not solidify before the glass. The metal used can be (2003)
(1)tin 2) sodium
3) magnesium 4) mercury
Ans. (4) It is because mercury is a liquid at room temperature.
10. Which among the following factors is the most important in making fluorine the strongest oxidizing halogen? (2004)
(1)Electron affinity
(2)Bond dissociation energy
(3)Hydration enthalpy 4) Ionization enthalpy
Ans. (2) Lower dissociation energy of bonds in F2.
11. Which one of the following statements regarding helium is incorrect? (2004)
(1) It is used to fill gas balloons instead because it is lighter and non-inflammable
(2)It is used in gas-cooled nuclear reactors
(3)It is used to produce and sustain powerful superconducting reagents (4)It is used as a cryogenic agent for carrying out experiments at low temperatures
Ans. (1) Hydrogen is lightest and is noninflammable.
Ans. (4) Hydrated and coordinated aluminium cations are farmed.
13. The soldiers of Napolean’s army, while in the Alps during freezing winter, suffered a serious problem as regards the tin buttons of their uniforms. White metallic tin buttons got converted to grey powder. This transformation is related to(2004)
(1)an interaction with the nitrogen of the air at very low temperatures
(2)an interaction with water vapor contained in the humid air
(3)a change in the partial pressure of oxygen in the air
(4)a change in the crystalline structure of tin
Ans. (4) Transformation of crystal structure.
14. The number of hydrogen atom(s) attached to phosphorus atom in hypophosphorous acid is
(2005)
(1)zero 2) two 3) one 4) three
Ans.
15. The correct order of the thermal stability of hydrogen halides (H – X) is (2005)
(1)HI > HBr > HC1 > HF
(2)HF > HC1 > HBr > HI
(3)HC1 < HF > HBr < HI
(4)HI > HC1 < HF < HBr
Ans. (2) HF is the most stable.
16. Heating an aqueous solution of aluminium chloride to dryness will give (2005)
(1)A1C13 2) A12C16
3) A1203 4) Al(OH)CI2
Ans.
17. In silicon dioxide (2005)
(1)Each silicon atom is surrounded by four oxygen atoms, and each oxygen atom is bonded to two silicon atoms
(2)Each silicon atom is surrounded by two oxygen atoms, and each oxygen atom is bonded to two silicon atoms
(3)Silicon atoms are bonded to two oxygen atoms
(4)There are double bonds between silicon and oxygen atoms
Ans.
18. The structure of diborane (B2Hfi) contains(2005)
(1)four 2c-2e bonds and two 3c-2e bonds
(2)two 2c-2e bonds and four 3c-2e bonds
(3)two 2c-2e bonds and two 3c-3e bonds
(4)four 2c-2e bonds and four 3c-2e bonds
Ans.
19. Which of the following chemical reactions depicts the oxidizing behaviour of H2S04?
(1)2HI + H2S04 -> I2 + S02 + 2H20 (2006)
(2)Ca(OH)2 + H2S04 CaS04 + 2H20
(3)NaCl + H2S04 NaHS04 + HC1
(4)2PC1S + H2S04 2POCl3 + 2HC1 + S02C12
Ans.
20. A metal, M, forms chlorides in its +2 and 44 oxidation states. Which of the following statements about these chlorides is correct?
(1)MC12 is more volatile than MC14 (2006)
(2)MC12 is more soluble in anhydrous ethanol than MC14
(3)MC12 is more ionic than MC14
(4)MC12 is more easily hydrolyzed than MC14
Ans.
21. Which of the following statements is true?
(1)H3PO3 is a stronger acid than H2S03 (2006)
(2)In an aqueous medium, HF is a stronger acid than HC1
(3)HC104 is a weaker acid than HC103
(4)HNO3 is a stronger acid than HN02
Ans.
22. What products are expected from the disproportionation reaction of hypochlorous acid? (2006)
(1)HCIO3 and C120 2) HC102 and HC104
3) HC1 and C120 4) HC1 and HC103
Ans.
23. The decreasing values of bond angles from NH3 (106°) to SbH3 (101°) down group-15 of the periodic table is due to (2006)
(!)increasing bp-bp repulsion
(2)increasing p-orbital character in sp3
(3)decreasing lp-bp repulsion
(4)decreasing electronegativity
Ans. (4) Repulsions will be less with lower electronegativity.
Ans.
Ans.
26. Identify the incorrect statement among the following (2007)
(1)Ozone reacts with S02 to give S03
(2)Silicon reacts with aqueous NaOH in the presence of air to give NajS^ and H20
(3)Cl2 reacts with an excess of NH3 to give N2 and HC1
(4)Br2 reacts with hot and strong NaOH solution to give NaBr, NaBr04, and H20
Ans.
Ans.
28. Which one of the following is the correct statement? (2008)
(1)Boric acid is a protonic acid
(2)Beryllium exhibits a coordination number of six.
(3)Chlorides of both beryllium and aluminum have bridged chloride structures in solid phase
(4)B2H6.2NH3 is known as ‘inorganic benzene.’
Ans.
29. In which of the following arrangements the e sequence is not strictly according to the property written against it? (2009)
(1)C02 < Si02 < Sn02 < Pb02 : increasing oxidising power
(2)HF < HC1 < HBr < HI : increasing acid strength
(3)NH3 < PH3 AsH3 < SbHj : increasing basic strength
(4)B<C<0<N: increasing first ionization enthalpy
Ans.
Ans. (1) Xe03 is more stable than XeF6. All the remaining reactions are feasible.
Ans.
Ans.
33. Which of the following statements regarding sulphur is incorrect? (2011)
(1) At 600°C the gas mainly consists of S2 molecules
(2) The oxidation state of sulphur is never less than + 4 in its compounds
(3) S, the molecule is paramagnetic
(4) The vapour at 200°C consists mostly of S8 rings
Ans.(2) Sulphur can exhibit – 2, + 2, + 1 oxidation states also.
Ans. (3) Stability of VA group hybrids decreases from NH3 to BiH3 due to the decrease in M – H bond energy.
NH3 > PH3 > AsH3 > SbH3 > BiH3
35. Which of the following on thermal decomposition yields a basic and an acidic oxide? (2012)
1) NaN03 2) KC103
3) CaC03 4) NH4N03
Ans.
Ans. (1) ONF and ONO– are isoelectronic ON Cl and ONS– are isoelectronic
37. Which one of the following properties is not shown by NO ? (2014)
(1) Its bond order is 2.5.
(2)It is diamagnetic in a gaseous state
(3)It is a neutral oxide
(4)It combines with oxygen to form nitrogen dioxide
Ans.(2) NO is paramagnetic.
38. Among the following oxoacids, the correct decreasing order of acid strength is (2014)
(1)HC102 > HC104 > HCIO, > HOC1
(2)HCIO > HC102 > HCIO3 > HOCl4
(3)HC104 > HCIO > HC102 > HOCl3
(4)HC102 > HCIO3 > HC102 > HOC1
Ans. (4) With an increase in unprotonated oxygen atoms, acidic strength increases.
39. In the context of the Hall-Heroult process for extracting Al, which of the following statements is false? (2015)
(1)CO and C02 are produced in this process
(2)A/203 is mixed with CaF2, which lowers the melting point of the mixture and brings conductivity
(3)A/3+ is reduced at the cathode to form Al
(4)Na3A/F6 serves as the electrolyte
Ans.[4] A/203 is dissolved in cryolite, which is an electrolyte in a molten state.
40. Which among the following is the most reactive? (2015)
1) C/2 2) Br2 3) I2 4) ICI
Ans.[4] Interhalogen compounds are polar and are more reactive.
41. Which one has the highest boiling point? (2015)
(1) He 2) Ne 3) Kr (4) Xe
Ans.[4] The boiling point increases with an increase in Molecular mass.
