Study Material
p-BLOCK ELEMENTS
Very Short Answer Questions
Q1. Why does the reactivity of nitrogen differ from phosphorus?
Q2. How is nitrogen prepared in the laboratory? Write the chemical equations of the reactions involved.
Q3. Nitrogen exists as diatomic molecule and phosphorus as P?-Why?
Q4. Why does nitrogen show catenation properties less than phosphorus?
Q5. Nitrogen molecule is highly stable - Why?
Q6. Why are the compounds of bismuth more stable in +3 oxidation state?
Q7. What is allotropy? Explain the different allotropic forms of phosphorus.
Q8. How do you account for the inert character of dinitrogen?
Q9. Explain the difference in the structures of white and red phosphorus.
Q10. How is $\alpha$ black phosphorus prepared from red phosphorus ?
Q11. Write the difference between the properties of white phosphorus and red phosphorus.
Q12. What is inert pair effect?
Q13. Explain why is $\ce{NH3}$ basic while $\ce{BiH3}$ is only feebly basic.
Q14. Arrange the hydrides of group 15 elements in the increasing order of basic strength and decreasing order of reducing character.
Q15. $\ce{PH3}$ is a weaker base than $\ce{NH3}$ - Explain.
Q16. A hydride of group 15 elements dissolves in water to form a basic solution. This solution dissolves the $\ce{AgCl}$ precipitate. Name the hydride. Write the chemical equations involved.
Q17. What happens when white phosphorus is heated with conc. $\ce{NaOH }$solution in an inert atmosphere of $\ce{CO2}$?
Q18. $\ce{ NH}$ forms hydrogen bonds but $\ce{PH3}$, does not - Why?
Q19. The $\ce{HNH }$ angle is higher than$\ce{ HPH, HAsH}$ and $\ce{HSbH}$ angles-Why?
Q20. How do calcium phosphide and heavy water react?
Q21. Ammonia is a good complexing agent - explain with an example.
Q22. A mixture of $\ce{Ca3 P2}$ and $\ce{CaC2}$ is used in making Holme's signal - explain.
Q23. Which chemical compound is formed in the brown ring test of nitrate ions?
Q24. Give the resonating structures of $\ce{NO2}$ and $\ce{N2O5}$
Q25. Why does$\ce{ R3P=0}$ exist but $\ce{R3N =0}$ does not (R=alkyl group)?
Q26. How is nitric oxide$\ce{ (NO) }$prepared?
Q27. Give one example each of normal oxide and mixed oxide of nitrogen.
Q28. NO is paramagnetic in gaseous state but diamagnetic in liquid and solid states - Why?
Q29. Give an example of a) acidic oxide of phosphorus b) neutral oxide of nitrogen
Q30. Explain the following a) reaction of alkali with red phosphorus b) reaction between $\ce{PCI3}$ and $\ce{H3PO3}$
Q31. How does $\ce{PCI3}$ react with a) $\ce{CH3COOH}$ b) $\ce{C2H5OH}$ and el water
Q32. $\ce{PCI3}$ can act as an oxidizing as well as a reducing agent - Justify.
Q33. Which of the following are not known? $\ce{PCI3}$, $\ce{AsCI3}$ , $\ce{SbCI3}$ , $\ce{NCI5}$, $\ce{BiCI5}$, $\ce{PCI5}$.
Q34. Which of the following is more covalent - $\ce{SbCI5}$ or $\ce{SbCI3}$?
Q35. Write the oxidation states of phosphorus in solid $\ce{PCI5}$.
Q36. Illustrate how copper metal can give different products on reaction with $\ce{HNO3}$
Q37. Which oxide of nitrogen has oxidation number of N same as that in nitric acid ?
Q38. Write the chemical reactions, that occur in the manufacture of nitric acid.
Q39. Iron becomes passive in conc.$\ce{HNO3}$ - Why?
Q40. Give the uses of a) nitric acid and b) ammonia
Q41. What are the oxidation states of phosphorus in the following? i) $\ce{H3PO3}$, ii) $\ce{PCI3}$ iii) $\ce{Ca3 P2}$ iv) $\ce{Na3PO4}$ v) $\ce{POF3}$
Q42. $\ce{H3PO3}$ is diprotic while $\ce{H3PO2}$ is monoprotic - Why?
Q43. Give the disproportionation reaction of $\ce{H3PO3}$
Q44. $\ce{H3PO2}$, is a good reducing agent-Explain with an example.
Q45. Draw the structures of (a) Hypo phosphoric acid (b) Cyclic meta phosphoric acid
Q46. Why is dioxygen a gas but sulphur a solid ?
Q47. What happens when a) $\ce{ KCIO3}$, is heated with $\ce{ MnO2}$ b) $\ce{ O3}$ is passed through KI solution
Q48. Give two examples each for amphoteric oxides and neutral oxides
Q49. Oxygen generally exhibits an oxidation state of -2 only while the other members of the group show oxidation states of +2, +4 and +6 also - explain.
Q50. Write any two compounds, in which oxygen shows an oxidation state different from-2. Give the oxidation states of oxygen in them.
Q51. Oxygen molecule has the formula $\ce{ O2}$ while sulphur has $\ce{ S8}$- explain
Q52. Why is $\ce{ H2O}$ a liquid while $\ce{ H2S}$ is a gas?
Q53. $\ce{ H2O}$ is neutral while $\ce{ H2S}$ is acidic-explain
Q54. Name the most abundant element present in earth's crust.
Q55. Which element of group- 16 shows highest catenation?
Q56. Among the hydrides of chalcogens, which is most acidic and which is most stable?
Q57. Give the hybridization of sulphur in the following. (a) $\ce{ SO2}$ (b) $\ce{ SO3}$(c) $\ce{ SF4}$ (d) $\ce{ SF6}$
Q58. Write the names and formulae of any two oxyacids of sulphur. Indicate the oxidation state of sulphur in them.
Q59. Explain the structures of $\ce{ SF4}$ and $\ce{ SF6}$
Q60. Give one example each for a) a neutral oxide b) a peroxide c) a super oxide
Q61. What is tailing of mercury? How is it removed?
Q62. Write the principle involved in the quantitative estimation of ozone gas.
Q63. Write the structure of ozone.
Q64. $\ce{ SO2}$ can be used as an anti-chlor. Explain.
Q65. How is ozone detected?
Q66. How does ozone react with ethylene?
Q67. Out of $\ce{ O2}$ and $\ce{ O3}$ which is paramagnetic?
Q68. Between $\ce{ O3}$ and $\ce{ O2}$ ozone is a better oxidizing agent - why?
Q69. Write any two uses each for $\ce{ O3}$ and $\ce{ H2SO4}$
Q70. Which form of sulphur shows paramagnetism?
Q71. How is the presence of $\ce{ SO2}$ detected?
Q72. Why are group - 16 elements called chalcogens?
Q73. Among chalcogens, which has highest electronegativity and which has highest electron gain enthalpy?
Q74. Which hydride of group 16 has highest boiling point and weakest acidic character?
Q75. Which halogen produces $\ce{O2}$ and $\ce{O3}$ on passing through water?
Q76. Interhalogen compounds are more reactive than the constituent halogens except fluorine - explain.
Q77. What is the use of $\ce{CIF3}$?
Q78. Write two uses of $\ce{CIO2}$
Q79. Why are halogens coloured?
Q80. Write the reactions of $\ce{F2}$ and $\ce{Cl2}$ with water.
Q81. With which neutral molecule, $\ce{CID^-}$ is isoelectronic? Is that molecule a Lewis base?
Q82. Arrange the following in the order of the property indicated for each set. a) $\ce{F2 , CL2 , Br2, I2,}$ Increasing bond dissociation enthalpy. b) $\ce{HF, HCl, HBr, HI-}$Increasing acidic strength. c) $\ce{HF, HCl, HBr, HI -}increasing boiling points.
Q83. Electron gain enthalpy of fluorine is less than that of chlorine-explain.
Q84. $\ce{HF}$ is a liquid while $\ce{HCI}$ is a gas - explain.
Q85. Bond dissociation enthalpy of $\ce{F2}$ is less than that of $\ce{Cl2}$ - explain.
Q86. Write the formulae of the compounds, in which oxygen has positive oxidation states and mention the oxidation states of oxygen in them.
Q87. What is the use of $\ce{O2F5}$, and $\ce{I2O5}$?
Q88. Write two uses of hydrogen chloride.
Q89. Explain the reactions of Cl, with NaOH.
Q90. What happens when Cl, reacts with dry slaked lime ?
Q91. Chlorine acts as an oxidizing agent explain with two examples.
Q92. What is aqua regia? Write its reaction with gold and platinum.
Q93. How is chlorine manufactured by Deacon's method?
Q94. Chlorine acts as a bleaching agent only in the presence of moisture - explain.
Q95. The decreasing order of acidic character among hypohalogen acids is HCIO > HBrO > HIO. Give reason.
Q96. The acidic nature of the oxoacids of chlorine is $\ce{ HOCI < HCIO2
Q97. What are interhalogen compounds? Give two examples.
Q98. Explain the structure of $\ce{CIF3}$
Q99. $\ce{OF2}$ should be called oxygen difluoride and not fluorine oxide - Why?
Q100. Iodine is more soluble in KI than in water - Explain.
Q101. Among the hydrides of halogens a) which is most stable? b) which is most acidic ? c) which has lowest boiling point?
Q102. Compare the bleaching action of $\ce{ Cl2}$ and $\ce{ SO2}$
Q103. Give the oxidation states of halogens in the following: a) $\ce{ Cl2O}$ b) $\ce{ CIO2}$ c) $\ce{ KBrO3}$, d) $\ce{ NaCIO4}$
Q104. Describe the molecular shape of $\ce{ I^- _3}$.
Q105. What inspired Bartlett for carrying out reaction between Xe and $\ce{PtF6}$?
Q106. Which of the following does not exist? a) $\ce{XeOF4}$ b) $\ce{NeF2}$ c) $\ce{XeF2}$ d) $\ce{XeF6}$
Q107. Why do noble gases have comparatively large atomic sizes ?
Q108. List out the uses of neon.
Q109. Write any two uses of argon.
Q110. In modern diving apparatus, a mixture of $\ce{He}$ and $\ce{O2}$ is used - Why?
Q111. Helium is heavier than hydrogen. Yet helium is used (instead of $\ce{H2}$) in filling balloons for meteorological observations - Why?
Q112. How is $\ce{XeO3}$ prepared?
Q113. Give the preparation of a) $\ce{XeOF4}$, and b) $\ce{XeO2F2}$
Q114. Explain the structure of $\ce{XeO3}$
Q115. Noble gases are inert - explain.
Q116. Write the name and formula of the first noble gas compound prepared by Bertlett.
Q117. Explain the shape of $\ce{XeF4}$, on the basis of VSEPR theory.
Q118. Give the outer electronic configuration of noble gases.
Q119. Why do noble gases form compounds with fluorine and oxygen only?
Q120. How is $\ce{XeOF4}$, prepared? Describe its molecular shape.
Q121. What is the major source of helium?
Q122. Which noble gas is radioactive? How is it formed?
Q123. Name the following a) most abundant noble gas in atmosphere b) radioactive noble gas c) noble gas with least boiling point d) noble gas forming large number of compounds e) noble gas not present in atmosphere
Q1. Discuss the general characteristics of Group-15 elements with reference to their electronic configuration, oxidation state, atomic size, ionization enthalpy and electronegativity.
Q2. Discuss the trends in chemical reactivity of group - 15 elements.
Q3. How does $\ce{P4}$ react with the following?(a) $\ce{SOCI2}$ (b) $\ce{SO2Cl2}$
Q4. Explain the anomalous nature of nitrogen in group - 15.
Q5. Complete the following reactions (a) $\ce{Ca3P2 + H2O ->}$ b)$\ce{ P4+KOH ->}$ (c) $\ce{CuSO4 + NH3 ->}$ d)$\ce{ Mg + N2 ->}$ e) $\ce{ (NH4)2Cr2O7 ->}$ f) Decomposition of nitrous acid
Q6. How does $\ce{PCI5}$ react with the following?a) Water b) $\ce{ C2H2OH}$ c) $\ce{ CH3COOH}$ d) Ag
Q7. Complete the following a) $\ce{ NH4NO3 ->}$ b) $\ce{ HNO3 + P4O10 ->}$ c) $\ce{ Pb(NO3)2}$ d) $\ce{ Zn+dil. HNO3 -> }$ e) $\ce{ P+conc.HNO3 -> }$ f) $\ce{ HgCl2+PH3 -> }$
Q8. Justify the placement of $\ce{ O, S, Se,Te and Po }$ in the same group of the periodic table in terms of electronic configuration, oxidation states and hydride formation
Q9. Describe the manufacture of $\ce{ H2SO4}$ by contact process.
Q10. How is ozone prepared? How does it react with the following? a) PbS b) KI c) Hg d) Ag
Q11. Write a short note on the allotropy of sulphur
Q12. How does $\ce{ SO2}$ react with the following? a) $\ce{ Na2SO3 (aq) }$ b)$\ce{ Cl2}$ c) $\ce{ Fe^{+3}}$ lons d)$\ce{ KMnO4}$
Q13. Starting from elemental sulphur, how is $\ce{ H2SO4}$ prepared?
Q14. Describe the structures (shapes) of $\ce{ SO_4^{-2}}$ and $\ce{ SO3}$
Q15. Which oxide of sulphur can act as both oxidizing and reducing agent? Give one example each
Q16. Explain the conditions favourable for the formation of $\ce{ SO3}$
Q17. from $\ce{ SO2}$ in the contact process of $\ce{ H2SO4}$
Q18. Complete the following a) $\ce{KCl+ H2SO4(conc) ->}$ b) Sucrose( Conc.$\ce{(H2SO4)} c) $\ce{Cu + H2SO4(conc)->}$ d) $\ce{C+H2SO4(conc) ->}$
Q19. Which is used for drying ammonia?
Q20. Why conc $\ce{ H2SO4}$ , $\ce{P4O10}$, and anhydrous $\ce{CaCl2}$ cannot be used to dry ammonia?
Q21. How can you prepare $\ce{ Cl2}$ from $\ce{ HCI}$ and $\ce{ HCI}$ from $\ce{ Cl2}$,? Write the reactions.
Q22. Write balanced equations for the following. a) $\ce{ NaCl}$ is heated with cone. $\ce{ H2SO4}$ in the presence of $\ce{ MnO2}$ b) Chlorine is passed into a solution of Nal in water.
Q23. Explain the structures of a) $\ce{ BrF5}$ and b) $\ce{ IF7}$
Q24. Write a short note on the hydrides of halogens.
Q25. How is chlorine obtained in the laboratory? How does it react with the following? a) cold dil.NaOH b) excess $\ce{ NH3}$ c)$\ce{ KI}$
Q26. What are interhalogen compounds? Give some examples to illustrate the definition. How are they classified?
Q27. How are xenon fluorides $\ce{XeF2}$, $\ce{XeF4}$, and $\ce{XeF6}$ obtained?
Q28. How are $\ce{XeO3}$, and $\ce{XeOF4}$, prepared?
Q29. Give the formulae and describe the structures of a noble gas species, Isoelectronic with a) $\ce{ICI4}$ b) $\ce{IBr_3^-}$ c) $\ce{BrO_3^-}$
Q30. Explain the reaction of the following with water a) $\ce{XeF2}$ b) $\ce{XeF4}$ c) $\ce{XeF6}$
Q31. Explain the structures of a) $\ce{XeF2}$ and b) $\ce{XeF6}$
Q32. Explain the structures of a) $\ce{XeF6}$ and b) $\ce{XeF4}$
Q33. Complete the following. a) $\ce{XeF2 + H2O -> }$ b) $\ce{ XeF2 + PF5 -> }$ c) $\ce{XeF4 +SbF5 -> }$ d) $\ce{ XeF6 + AsF5 -> }$ e) $\ce{XeF4 +O2F2 ->}$ f) $\ce{NaF+XeF6 -> }$
Q34. How are $\ce{XeF2}$ and $\ce{XeF4}$ prepared? Give their structures.
Q1. How is ammonia manufactured-by Haber's process? Explain the reactions of ammonia with (a) $\ce{ ZnSO4 (aq)}$ (b) $\ce{ CuSO4 (aq)}$ (c) $\ce{ AgCl (s)}$
Q2. How is nitric acid manufactured by Ostwald's process? How does it react with the following? (a) Copper (b) $\ce{ Zn}$ (c) $\ce{ S8}$ (d) $\ce{ P4}$
Q3. Explain in detail the manufacture of sulphuric acid by contact process.
Q4. How is ozone prepared from oxygen? Explain its reaction with a) $\ce{C2H4}$ b) $\ce{KI}$ c) $\ce{Hg}$ d) $\ce{PbS}$
Q5. How is $\ce{ CIF3}$, prepared? How does it react with water? Explain its structure.
Q6. How is chlorine prepared in the laboratory? How does it react with the following? a) Iron b) hot, cone. NaOH c) acidified e) $\ce{FeSO4}$ d) lodine e) $\ce{H2S}$ f) $\ce{ Na2S2O3}$
Q7. Discuss the anomalous behaviour of fluorine.
Q8. How is chlorine prepared by electrolytic method? Explain its reaction with a) $\ce{ NaOH}$ and b)$\ce{ NH3}$ under different conditions.
Q9. Write the names and formulae of the oxoacids of chlorine. Explain their structures and relative acidic nature.
Q10. How are $\ce{XeF2 , XeF4 and XeF6 }$ prepared? Explain their reaction with water. Discuss their structures.