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This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Assertion: Changes in packaging have resulted in much of our waste becoming nonbiodegradable. Reasons: Changes in attitude also have a role to play, with more and more things we use becoming disposable.a) Both A and R are true, and R is correct explanation of the assertion. b) Both A and R are true, but R is not the correct explanation of the assertion. c) A is true, but R is false.d) A is false, but R is true |
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Answer» a) Both A and R are true, and R is correct explanation of the assertion. |
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| 2. |
What is translocation? Which structure of phloem is responsible for translocation of food in plants? |
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Answer» Transport of soluble product of photosynthesis or food from leaves to other parts of plants is called translocation. For translocation, food molecules enter the part of the phloem called the sieve tubes, where they can be transported upwards or downwards to all parts of the plant including roots. Translocation is achieved by utilizing energy from the ATP that provides osmotic pressure required for upward and downward movement of food. |
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| 3. |
Cassiterite is an ore of :A. MnB. NiC. SbD. Sn. |
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Answer» Correct Answer - D Cassiterite `(SnO_(2))` is an ore of tin. |
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| 4. |
Which of the following minerals does not contain aluminium ?A. Fluorspar B. FeldsparC. CryoliteD. Mica |
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Answer» Correct Answer - A Fluorspar is `CaF_(2)` |
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| 5. |
Copper is the most noble of first row transition metals and occurs in small deposits in serveral countries. Ores of copper include chalcanthite `(CuSO_(4).5H_(2)O)`, atacanite `[Cu_(2)Cl(OH)_(3)]`, cuprite `(Cu_(2)O)`, copper glance `(Cu_(2)S)`, and malachite `[Cu_(2)(OH)_(2)CO_(3)]`. However, `80 %` of the world copper production comes from the ore chalcopyrite `(CuFeS_(2))`. The extraction of copper from chalcopyrite involves partial roasting, removal of iron and self-reduction. Iron is removed from chalcopyrite as.A. `FeO`B. `FeS`C. `Fe_(2)O_(3)`D. `FeSiO_(3)` |
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Answer» Correct Answer - D Removal of iron : `FeO + SiO_(2) rarr FeSiO_(3)` (Slag). |
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| 6. |
Amongst the following the total number of elements, which produce `H_(2) ` gas with sodium hydroxide is `:` `Zn,Al,Sn,Pb,P,Si`A. 3B. 4C. 5D. 6 |
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Answer» Correct Answer - C `Zn+2NaOHrarrNa_(2)ZnO_(2)+H_(2)uarr` `2Al+2NaOH+H_(2)Orarr2NaAlO_(2)+3H_(2)uarr` `Sn+2NaOH+H_(2)OrarrNa_(2)SnO_(3)+2H_(2)uarr` `Pb+2NaOH+H_(2)OrarrNa_(2)PbO_(3)+2H_(2)uarr` `Si+2NaOH+H_(2)O rarr Na_(2)SiO_(3)+2H_(2)uarr` `P_(4)+3NaOH+3H_(2)O rarr PH_(3)uarr+3NaH_(2)PO_(2)` |
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| 7. |
In the extraction of iron, the slag produced is :A. COB. `FeSiO_(3)`C. `MgSiO_(3)`D. `CaSiO_(3)` |
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Answer» Correct Answer - D Calcium silicate is the slag. |
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| 8. |
In electrorefining of copper,some gold is deposited asA. cathodeB. electrodeC. cathode mudD. anode mud |
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Answer» Correct Answer - D In electro refining of Cu, the impurities of Ni, Fe and Zn pass into solution as sulphate while impurity of Ag , Au and Sn etc. , are thrown down as anode mud |
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| 9. |
In the commercial electrochemical process for aluminium extraction, the electrolyte used isA. an aqueous solution of `Al_(2)(SO_(4))_(3)`B. an aqueous solution of `Al(OH)_(3)` and `NaOH`C. a molten mixture of `Al(OH)_(3) and CaCO_(3)`D. a molten mixture of `Al_(2)O_(3) and Na_(3)AlF_(6)` |
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Answer» Correct Answer - D Impurity in solid decreases melting point . |
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| 10. |
Copper is the most noble of first row transition metals and occurs in small deposits in serveral countries. Ores of copper include chalcanthite `(CuSO_(4).5H_(2)O)`, atacanite `[Cu_(2)Cl(OH)_(3)]`, cuprite `(Cu_(2)O)`, copper glance `(Cu_(2)S)`, and malachite `[Cu_(2)(OH)_(2)CO_(3)]`. However, `80 %` of the world copper production comes from the ore chalcopyrite `(CuFeS_(2))`. The extraction of copper from chalcopyrite involves partial roasting, removal of iron and self-reduction. In self-reduction, the reducing species is.A. SB. `O^(2-)`C. `S^(2-)`D. `SO_(2)` |
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Answer» Correct Answer - C Self-reduction : `Cu_(2)S + 2Cu_(2) O rarr 6Cu + SO_(2)` The oxidation number of sulphur increases from `-1` to `+4`. Therefore, `S^(2-)` is the reducing species. |
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| 11. |
Which one of the following is not correct for the allotropic forms of carbon ?A. `C_(60)` molecule has a shape like soccer ball and calledB. Graphite is thermodynamically most stable allotrope of carbon.C. Graphite fibres embedded in plastic material from high strength, lightweight composites.D. In diamond each carbon atom undergoes `sp^(3)` hybridisation and is paramagnetic. |
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Answer» Correct Answer - 4 Diamond is diamagnetic as there is no unpaired electron. |
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| 12. |
In the extractionof iron, slag is produced. Slag isA. COB. `FeSiO_(3)`C. `MgSiO_(3)`D. `CaSiO_(3)` |
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Answer» Correct Answer - B In the extraction of Fe, slag produced in `FeSiO_3` `FeO+SiO_(2) to FeSiO_(3)` |
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| 13. |
An organic solid (A) on heating gives a green residue (B), a colourless gas (C) and water vapours. The dry gas (C) passing over heated Mg gave a white solid (D). (D) on reaction with water give a gas (E) which formed dense white fumes with HCl. Identify (A) to (E) and give the reactions involved. |
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Answer» A = (NH4)2Cr2O7 B = Cr2O3 C = N2 D = Mg3N2 E = NH3 |
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| 14. |
Fluorine does not show positive oxidation state. Why? |
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Answer» It is the most electro negative element. So, whenever it is bonded with any other atom, the bond pair is shifted towards F only. |
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| 15. |
Select the incorrect statement ?A. `._(7)N` has higher `1^(st)` ionization enthalpy than that of `._(8)O` atom.B. `._(12)Mg` has higher `1^(st)` ionization enthalpy than that of `._(13)Al` atom.C. `._(31)Ga` has higher `1^(st)` ionization enthalpy than that of `._(13)Al` atom.D. `._(16)S` has higher `1^(st)` ionization enthalpy than that of `._(8)O` atom. |
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Answer» Correct Answer - 4 Down the group, the size of atom increases and therefore, distance between valence shell electron and nucleus increase. Thus the removal of valence shell electron will require less energy. |
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| 16. |
In the electrolysis of alumina , cryolite and `CaF_(2)` are added toA. increase the emf of cellB. decrease the emf of cellC. decrease the melting pointD. Both (b) and (c) |
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Answer» Correct Answer - C Cryolite and `CaF_2`(fluorspar) are added to alumina in its electrolysis to decrease its melting point and to increase the electrical conductivity . |
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| 17. |
In the electrolysis of alumina, cryolite is added toA. Lower the melting point of aluminaB. Increase the electrical conductivityC. Minimise the anode effectD. Remove the impurities from alumina |
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Answer» Correct Answer - A::B The electrolysis of pure alumina faces some difficulties. Pure alumina is a bad conductor is of electricity. This fusion temperature of pure alumina is about `2000^@C`, and at this temperature, when the electrolysis is carried out on the fused mass, the metal formed vaporises as the boiling point aluminium is `1800^@ C`. These difficulties are overcome by using a mixture containing alumina, cryolite `(Na_(3)AlF_(6))`, and fluorpar `(CaF_(2))`. |
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| 18. |
In the electrolysis of alumina, cryolite is added toA. decrease the electrical conductivityB. remove impurities from aluminaC. lower the melting point of aluminaD. minimise the anode effect |
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Answer» Correct Answer - C Impurity in solid decreases melting point . |
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| 19. |
Nitrate of which of the following elements are converted to their oxides on heating ? (a) Li (b) Na (c) K (d) Mg |
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Answer» (a) Li (d) Mg |
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| 20. |
When sulfuring acid reacts with copper, how does the oxidation of number of the sulfur change ? (a) From + 4 to + 6 (b) From + 6 to + 4 (c) From + 6 to + 8 (d) From + 8 to + 6 |
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Answer» (a) From + 4 to + 6 |
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| 21. |
Which is deliquescent? (a) MgCl2 (b) NaOH (c) CaCl2 (d) All |
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Answer» (d) All of these Explanation: Because MgCl2, NaOH and CaCl2 all absorbs water from the atmospheric moisture. |
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| 22. |
Which of the following statements is true about the `14^(th)` group elements ?A. The stability of their dihalides increases steadily in the order `:PbX_(2) lt SnX_(2) lt GeX_(2) lt SiX_(2)`.B. The tendency of the elements to catenation decreases as `C gt Si gt Ge ~~ Sn gt Pb`C. Both `[SiF_(6)]^(2-)` and `[SiCl_(6)]^(2-)` are known.D. Silica is inert towards `NaOH` but it is attacked by HF forming `SiF_(4)`. |
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Answer» Correct Answer - 2 `(1)` Correct order is `SiX_(2) lt GeX_(2) lt SnX_(2) lt PbX_(2)` on account of inert pair effect. `(2)` Bond enthalpy `: " "C-C=348KJ mol^(-1)" "," "Si-Si=297KJ mol^(-1)` `" "Ge-Ge=260KJ mol^(-1)" "," "Sn-Sn=240KJ mol^(-1)` `(3)` `[SiF_(6)]^(2-)` existsbut `[SiCl_(6)]^(2-)` does not exist as smaller `Si` can not accomodate six larger chloride ions. `(4)` `SiO_(2)+2NaOH rarr Na_(2)SiO_(3)+H_(2)O, SiO_(2)+4HF rarr SiF_(4)+2H_(2)O` |
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| 23. |
The major role of fluorspar (CaF2), which is added in small quantities in the electrolytic reduction of alumina dissolved in fused cryolite (Na3AlF6), is (a) as a catalyst (b) to make the fused mixture very conducting (c) to lower the temperature of the melt (d) to decrease the rate of oxidation of carbon at the anode. |
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Answer» (b) to make the fused mixture very conducting (c) to lower the temperature of the melt |
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| 24. |
In the electrolysis of alumina, cryolite is added to: (a) lower the melting point of a alumina (b) increase the electrical conductivity (c) minimize the anode effect (d) remove impurities from alumina |
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Answer» (a) lower the melting point of a alumina (b) increase the electrical conductivity |
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| 25. |
Ammonium salts are oxidised in the oil to nitrites by (a) Denitrifying bacteria (b) Nitrifying bacteria (c) Ammonifying bacteria (d) Nitrosifying bacteria |
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Answer» (b) Nitrifying bacteria |
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| 26. |
The apparatus shown below can be used to prepare HNO3 (boiling point = 86°C).The yield of HNO3 collected in the tube can be maximized by maintaining the temperatures of the flask and tube, respectively, at (a) 0°C and 100°C (b) 100°C and 0°C (c) 350°C and 150°C (d) 350°C and 100°C |
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Answer» (b) 100°C and 0°C |
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| 27. |
Boric acid is `:`A. a tribasic and weak Bronsted acid.B. polymeric due to the presence of hydrogen bonds.C. obtained by the hydrolysis of only boron halides and not by the hydrolysis of boron hydrides with water or dilute acids.D. highly soluble in cold water. |
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Answer» Correct Answer - 2 `(1)` It is a weak monobasic Lewis acid. `(2)` It has layer structure in which planar `BO_(4)` units are joined by hydrogen bonds giving polymer structure. `(3)` Can be obtained by the hydrolysis of boron halids as well as boron hydrides with water or dilute acids. `(4)` It is sparingly in cold water and highly soluble in hot water. |
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| 28. |
Is there any coloured oxide of Nitrogen? |
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Answer» The known oxides of N are N2O , NO,NO2 , N2O3 , N2O4 and N2O5 . Among these NO2 is brown gas and N2O3 is blue coloured liquid. |
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| 29. |
Red lead on reaction with dil. HNO3 form (a) PbO (b) PbO2 (c) PbO + Pb(NO3)2 (d) PbO2 + Pb(NO3)2 |
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Answer» (d) PbO2 + Pb(NO3)2 Explanation: Pb3O4 + 4HNO3 → 2Pb(NO3)2 + PbO2 + 2H2O |
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| 30. |
Nitrogen (I) oxide is produced by : (a) thermal decomposition of ammonium nitrate (b) disproportion ation of N2O4 (c) thermal decomposition of ammonium nitrite (d) interaction of hydroxylamine and nitrous acid. |
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Answer» (a) thermal decomposition of ammonium nitrate (d) interaction of hydroxylamine and nitrous acid. |
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| 31. |
The following compounds have been arranged in the order of their increasing thermal stabilities. Identify the correct order. `K_(2)CO_(3)(I),Na_(2)CO_(3)(II),Rb_(2)CO_(3)(III),Li_(2)CO_(3)(IV)`A. `I lt II lt III lt IV`B. `IV lt II lt III lt I`C. `IV lt II lt I lt III`D. `II lt IV lt III lt I` |
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Answer» Correct Answer - 3 The thermal stabilites of carbonates increase down the group due to increase in metallic character `i.e.` electropositive character . Further bigger cation stabiliese bigger anion through crystal lattice energy effects. |
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| 32. |
The compounds used as refrigerant are (a) NH3 (b) CCl4 (c) CF4 (d) CF2Cl2 (e) CH2F2 |
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Answer» (a) NH3 (d) CF2Cl2 (e) CH2F2 |
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| 33. |
Which among the following compounds are paramagnetic (a) KO2 (b) K2O2 (c) K2O (d) NO2 |
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Answer» (a) KO2 (d) NO2 |
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| 34. |
In Holmes signals the compound used is (a) Ca3 P2 + CaC2 (b) CaC2 (c) Ca3P2 (d) CaCN2 + Ca3P2 |
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Answer» In Holmes signals the compound used is Ca3 P2 + CaC2. |
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| 35. |
Explain briefly: Why hydrazine is unstable? |
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Answer» In hydrazine, there is N—N single bond with a lone pair on each nitrogen. Due to the small size of nitrogen, there is considerable repulsion between these nonbonding electrons, thus weakening the N—N single bond. This makes hydrazine unstable. |
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| 36. |
Decomposition of H2O2 is slowed down by addition of (a) Alcohol (b) MnO2 (c) Alkali (d) Pt. |
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Answer» Decomposition of H2O2 is slowed down by addition of Alcohol. |
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| 37. |
The following compounds have been arranged in the order of increasing thermal stabilities. Identify the correct order. K2CO3(I), MgCO3 (II), CaCO3 (III), BeCO3 (IV)(a) I < II < III < IV (b) IV < II < III < I (c) IV < II < I < III (d) II < IV < III < I |
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Answer» (b) IV < II < III < I |
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| 38. |
A gas which burns with blue flame is (a) CO (b) O2 (c) N2 (d) CO2 |
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Answer» A gas which burns with blue flame is CO. |
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| 39. |
A mixture of hydrazine and H2O2 is (a) antiseptic (b) rocket fuel (c) germicide (d) insecticide |
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Answer» A mixture of hydrazine and H2O2 is insecticide. |
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| 40. |
The blue colour mineral lapis lazull which is used as a semi precious stone is a mineral of the following class (a) Sodium alumino silicate (b) Zinc cobaltate (c) Basic copper carbonate (d) Prussian blue. |
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Answer» (a) Sodium alumino silicate |
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| 41. |
Hydrolysis of one mole of peroxy disulphuric acid produces (a) two moles of sulphuric acid (b) two moles of peroxy monosulphuric acid (c) one mole of sulphuric acid and one mole of peroxy mono sulphuric acid (d) one mole of sulphuric acid, one mole of peroxy mono sulphuric acid and one mole of H2 O2 . |
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Answer» (c) one mole of sulphuric acid and one mole of peroxy mono sulphuric acid |
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| 42. |
How many of the following are paramagnetic? O22, He2-, C2, B2, Li2, O2+, O2- |
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Answer» Correct answer is 5.00 He2+, C2-, B2, O2- and O2- These are paramagnetic species due to presence to unpaired electron |
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| 43. |
The empirical formula of an acid is `CH_(2)O_(2)`, the probable molecular formula of acid may be :-A. `CH_(2)O`B. `CH_(2)O_(2)`C. `C_(2)H_(4)O_(2)`D. `C_(3)H_(6)O_(4)` |
| Answer» Correct Answer - A | |
| 44. |
Non combustible hydride is (a) NH3 (b) PH3 (c) AsH3 (d) SbH3 |
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Answer» Non combustible hydride is NH3. |
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| 45. |
Which of the following has maximum electron affinity ?(a) F(b) Cl(c) Br(d) I |
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Answer» Cl has maximum electron affinity . |
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| 46. |
Which of the following reagent turns lead acetate paper black ?(a) SO2(b) H2SO4(c) H2S(d) CO2 |
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Answer» H2S reagent turns lead acetate paper black. |
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| 47. |
Why bismuth does not from pentahalides? |
| Answer» Bismuth due to inert pair effect i.e., reluctance of `6s^2` electrons to unpair and participate in chemical bond formation does not form pentahalides. | |
| 48. |
What type of hydridisation is involveed in the formation of pentahalides is involved in the formation of pentahalides of group 15 elements? |
| Answer» In the formation of pentahalides of group 15 elements. `sp^3` d hydridisation is involved. | |
| 49. |
The tendency of nitrogen halides to act as Lewis bases decreases in the order.(a) NF3 > NCl3 > NBr3 > NI3(b) NI3 > NBr3 > NCl3 > NF3(c) NCl3 > NBr3 > NI3 > NF3(d) NI3 > NF3 > NCl3 > NBr3 |
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Answer» The tendency of nitrogen halides to act as Lewis bases decreases in the order NI3 > NBr3 > NCl3 > NF3 |
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| 50. |
Match appropriate pairs.Column - IColumn - II(P) Juvenile phase(i) Cell produed duringmeiosis(Q) Gametogenesis phase(ii) Conjugation phase of heterogenous meiotic cells(R) Gamete transfer phase(iii) Phase during which specific maturation occurs(S) Fertile phase(iv) The phase during which heterogenous meiotic division occur(a) P-i, Q-ii,R-iii, S-iv (b) P-iii, Q-i, R-iv,S-ii (c) P-ii, Q-iii, R-iv, S-i (d) P-iii, Q-i, R-ii, S-iv |
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Answer» (b) P-iii, Q-i, R-iv,S-ii |
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