Chapter 15 The p-block elements (I) Part1 The group 17elements(F,CI Br,I) 1.Which of the following correctly describes the trends in values of Pauling electronegativities(xP)and ionic radii(rion)? A.xP:FCl>Br>I;rion:FCl>Br>I D.xP:F>Cl>Br>I;rion:F>Cl>Br>I 2.The Br-Br distance in crystalline Br2 is 227 pm,but in the solid state structure of PhaPBr2 it is 312 pm.This is because: A.an ionic salt has formed B.electrons from a filled MO in Br2 have been donated to PPhs C.lone pair electrons from PPh3 have been donated to the Br2MO D.PhaPBr2 is trigonal bipyramidal and the two Br atoms are not bonded 3.Which statement is incorrect about the hydrogen halides? A.Each gaseous HX molecule is polar B.All are gases at 298K C.Bond dissociation energies for HX decrease down the group D.For each HX,the pK value is negative indicating that each is a strong acid 4.Match the shape to the formula.Which pairing is correct? A.[BrF2]';non-linear B.[ICl4]tetrahedral C.IFs;trigonal bipyramidal D.BrF,trigonal pyramidal
Chapter 15 The p-block elements ( ) Ⅲ Part1 The group 17 elements (F, Cl Br, I) 1. Which of the following correctly describes the trends in values of Pauling electronegativities (χP) and ionic radii (rion)? A. χP: F Cl > Br > I; rion: F Cl > Br > I D. χP: F > Cl > Br > I; rion: F > Cl > Br > I 2. The Br–Br distance in crystalline Br2 is 227 pm, but in the solid state structure of Ph3PBr2 it is 312 pm. This is because: A. an ionic salt has formed B. electrons from a filled MO in Br2 have been donated to PPh3 C. lone pair electrons from PPh3 have been donated to the Br2 σ* MO D. Ph3PBr2 is trigonal bipyramidal and the two Br atoms are not bonded 3. Which statement is incorrect about the hydrogen halides? A. Each gaseous HX molecule is polar B. All are gases at 298 K C. Bond dissociation energies for HX decrease down the group D. For each HX, the pKa value is negative indicating that each is a strong acid 4. Match the shape to the formula. Which pairing is correct? A. [BrF2] + ; non-linear B. [ICl4] – ; tetrahedral C. IF5; trigonal bipyramidal D. BrF3; trigonal pyramidal 1
5.Which reaction is not likely to occur? A.CsF+F7→CsF] B.CsF+BrF3→Cs[BrF4l C.2SbFs+BrFs[BrF4][Sb2Fn] D.CIF3+BF3-[BF2][CIF4] 6.Which of the following oxides is paramagnetic? A.Cl2O B.C102 C.C1206 D.C10 7.Cl2O7 is the anhydride of: A.HOCI B.HClO2 C.HCIO; D.HCIO4 8.Which statement is incorrect about oxoacids of the halogens? A.HCIO is a liquid at 298 K B.HOCI and HOBr have not been isolated C.HCIO and HCIO behave as weak acids in aqueous solution D.Aqueous HIO is relatively strong acid with pK< 9.Which statement about perchlorates is incorrect? A.[CIOis difficult to reduce in dilute solution because it is kinetically stable B.[CIO is a strongly coordinating ion and is much used in complex formation C.Perchlorates are potentially explosive D.The [CIOion is tetrahedral
5. Which reaction is not likely to occur? A. CsF + IF7 → Cs[IF8] B. CsF + BrF3 → Cs[BrF4] C. 2SbF5 + BrF5 → [BrF4][Sb2F11] D. ClF3 + BF3 → [BF2][ClF4] 6. Which of the following oxides is paramagnetic? A. Cl2O B. ClO2 C. Cl2O6 D. Cl2O7 7. Cl2O7 is the anhydride of: A. HOCl B. HClO2 C. HClO3 D. HClO4 8. Which statement is incorrect about oxoacids of the halogens? A. HClO4 is a liquid at 298 K B. HOCl and HOBr have not been isolated C. HClO4 and HClO3 behave as weak acids in aqueous solution D. Aqueous HIO3 is relatively strong acid with pKa < 1 9. Which statement about perchlorates is incorrect? A. [ClO4] – is difficult to reduce in dilute solution because it is kinetically stable B. [ClO4] – is a strongly coordinating ion and is much used in complex formation C. Perchlorates are potentially explosive D. The [ClO4] – ion is tetrahedral 2
10.Titration of I2 against thiosulfate is a standard laboratory titration.Which statement is correct? A.Solutions of are prepared in aqueous KI because I is insoluble in water B.is oxidized during the titration C.[S2O3is reduced during the titration D.No indicator is usually used in this redox titration 11.Which interhalogen compound or cation is not,at present,known? A.CIF7 B.[BrFcJ' C.IF7 D.[CIFsT 12.In which reaction is iodine oxidized? A.2+B2→2IBr B.IFs+2SbFs-[IF4][Sb2Fu] C.205+H0→2HIO3 D.IF3+MeNF→Me4NIF 13.In which solid-state structure is F-octahedrally sited? A.KF B.CaF2 C.BeF2 D.HF 14.Hypochlorous acid and perchloric acid are,respectively A.HOCI and HCIO4 B.HOCI and HCIO C.HCIO2 and HCIO D.HCIO2 and HCIO
10. Titration of I2 against thiosulfate is a standard laboratory titration. Which statement is correct? A. Solutions of I2 are prepared in aqueous KI because I2 is insoluble in water B. I2 is oxidized during the titration C. [S2O3] 2– is reduced during the titration D. No indicator is usually used in this redox titration 11. Which interhalogen compound or cation is not, at present, known? A. ClF7 B. [BrF6] + C. IF7 D. [ClF6] + 12. In which reaction is iodine oxidized? A. I2 + Br2 → 2IBr B. IF5 + 2SbF5 → [IF4][Sb2F11] C. I2O5 + H2O → 2HIO3 D. IF3 + Me4NF → [Me4N][IF4] 13.In which solid-state structure is F– octahedrally sited? A. KF B. CaF2 C. BeF2 D. HF 14. Hypochlorous acid and perchloric acid are, respectively: A. HOCl and HClO4 B. HOCl and HClO3 C. HClO2 and HClO3 D. HClO2 and HClO4 3
15.Which of the following statements is incorrect? A.KBrO is a strong reducing agent and is used in volumetric analysis B.HIO,is a white solid at 298K C.Perchlorate salts are potentially explosive D.NaClO;is a commercial bleaching agent 16.Match the following molecules or ions to their shapes.Which pairing is correct? A.[I3]';bent B.BrFs;trigonal bipyramidal C.CIF3;trigonal planar D.[BrF square planar 17.Consider [IFs]With which arrangement of atoms is the VSEPR model consistent? A.Trigonal bipyramidal B.Pentagonal planar C.Square-based pyramidal D.Pentagonal bipyramidal 18.A potential diagram for bromine at pH 14 shows the following E values BrOJ→Br-E=+0.61V BrOj→Br-E°=+0.76V What is the value of Eo for the reduction of [BrO3T to [BrO]? A.+0.54V B.-0.15V C.+0.46V D.+1.37V 19.Which one of the following is a disproportionation reaction?
15. Which of the following statements is incorrect? A. KBrO3 is a strong reducing agent and is used in volumetric analysis B. HIO3 is a white solid at 298 K C. Perchlorate salts are potentially explosive D. NaClO3 is a commercial bleaching agent 16. Match the following molecules or ions to their shapes. Which pairing is correct? A. [I3] - ; bent B. BrF5 ; trigonal bipyramidal C. ClF3 ; trigonal planar D. [BrF4] - ; square planar 17. Consider [IF5] 2-. With which arrangement of atoms is the VSEPR model consistent? A. Trigonal bipyramidal B. Pentagonal planar C. Square-based pyramidal D. Pentagonal bipyramidal 18. A potential diagram for bromine at pH 14 shows the following Eo values: [BrO3] - → Br- Eo = +0.61 V [BrO]- → Br- Eo = +0.76 V What is the value of Eo for the reduction of [BrO3] - to [BrO]- ? A. +0.54 V B. -0.15 V C. +0.46 V D. +1.37 V 19. Which one of the following is a disproportionation reaction? 4
A.l2+r→ B.Cl2+2[OH→C+[OCI叮+H20 C.B+3[OCI叮→BrO+3Cr D.HOI+2HCI→H++C+HO 20.In which one of the following reactions is at least one iodine atom oxidized? A.IFs+2SbFs-[IFa][Sb2Fu] B.CsIC]→CsCI+ICI C.2+r→ D.2L2+S206F2→2][S0,F] ANSWERS: 1.Which of the following correctly describes the trends in values of Pauling electronegativities(xP)and ionic radii(rion)? Correct Answer:xP:F>CI>Br>I;rion:F<CI<Br<I 2.The Br-Br distance in crystalline Br2 is 227 pm,but in the solid state structure of Ph3PBr2 it is 312 pm.This is because: Correct Answer:lone pair electrons from PPhs have been donated to the Br2MO 3.Which statement is incorrect about the hydrogen halides? Correct Answer:For each HX,the pKa value is negative indicating that each is a strong acid 4.Match the shape to the formula.Which pairing is correct? Correct Answer:[BrF2];non-linear 5.Which reaction is not likely to occur? Correct Answer:ClF3+BF3[BF2][CIFa] 6.Which of the following oxides is paramagnetic? Correct Answer:ClO2 7.C1207 is the anhydride of: Correct Answer:HCIO 8.Which statement is incorrect about oxoacids of the halogens?
A. I2 + I- → [I3] - B. Cl2 + 2[OH]- → Cl- + [OCl]- + H2O C. Br- + 3[OCl]- → [BrO3 ]- + 3Cl- D. HOI + 2HCl → H+ + [ICl2] - + H2O 20. In which one of the following reactions is at least one iodine atom oxidized? A. IF5 + 2SbF5 → [IF4][Sb2F11] B. Cs[ICl2] → CsCl + ICl C. I2 + I- → [I3] - D. 2I2 + S2O6F2 → 2[I2][SO3F] ANSWERS: 1. Which of the following correctly describes the trends in values of Pauling electronegativities (χP) and ionic radii (rion)? Correct Answer: χP: F > Cl > Br > I; rion: F < Cl < Br < I 2. The Br–Br distance in crystalline Br2 is 227 pm, but in the solid state structure of Ph3PBr2 it is 312 pm. This is because: Correct Answer: lone pair electrons from PPh3 have been donated to the Br2 σ* MO 3. Which statement is incorrect about the hydrogen halides? Correct Answer: For each HX, the pKa value is negative indicating that each is a strong acid 4. Match the shape to the formula. Which pairing is correct? Correct Answer: [BrF2] + ; non-linear 5. Which reaction is not likely to occur? Correct Answer: ClF3 + BF3 → [BF2][ClF4] 6. Which of the following oxides is paramagnetic? Correct Answer: ClO2 7. Cl2O7 is the anhydride of: Correct Answer: HClO4 8. Which statement is incorrect about oxoacids of the halogens? 5
Correct Answer:HCIO4 and HCIO3 behave as weak acids in aqueous solution 9.Which statement about perchlorates is incorrect? Correct Answer:[ClO]is a strongly coordinating ion and is much used in complex formation 10.Titration of 1 against thiosulfate is a standard laboratory titration.Which statement is correct? Correct Answer:Solutions of I2 are prepared in aqueous KI because I2 is insoluble in water 11.Which interhalogen compound or cation is not,at present,known? Correct Answer:CIF 12.In which reaction is iodine oxidized? Correct Answer:12+Br2-2IBr 13.In which solid-state structure is F-octahedrally sited? Correct Answer:KF 14.Hypochlorous acid and perchloric acid are,respectively Correct Answer:HOCI and HClO 15.Which of the following statements is incorrect? Correct Answer:KBrO3 is a strong reducing agent and is used in volumetric analysis 16.Match the following molecules or ions to their shapes.Which pairing is correct? Correct Answer:[BrF square planar 17.Consider [IFs With which arrangement of atoms is the VSEPR model consistent? Correct Answer:Pentagonal planar 18.A potential diagram for bromine at pH 14 shows the following Evalues: [BrOJ→BrE°=+0.61V BrOj→Br-E°=+0.76V What is the value of Eo for the reduction of [BrO to [BrO]? Correct Answer:+0.54 V 19.Which one of the following is a disproportionation reaction?
Correct Answer: HClO4 and HClO3 behave as weak acids in aqueous solution 9. Which statement about perchlorates is incorrect? Correct Answer: [ClO4] – is a strongly coordinating ion and is much used in complex formation 10. Titration of I2 against thiosulfate is a standard laboratory titration. Which statement is correct? Correct Answer: Solutions of I2 are prepared in aqueous KI because I2 is insoluble in water 11. Which interhalogen compound or cation is not, at present, known? Correct Answer: ClF7 12. In which reaction is iodine oxidized? Correct Answer: I2 + Br2 → 2IBr 13. In which solid-state structure is F– octahedrally sited? Correct Answer: KF 14. Hypochlorous acid and perchloric acid are, respectively: Correct Answer: HOCl and HClO4 15. Which of the following statements is incorrect? Correct Answer: KBrO3 is a strong reducing agent and is used in volumetric analysis 16. Match the following molecules or ions to their shapes. Which pairing is correct? Correct Answer: [BrF4] - ; square planar 17. Consider [IF5] 2-. With which arrangement of atoms is the VSEPR model consistent? Correct Answer: Pentagonal planar 18. A potential diagram for bromine at pH 14 shows the following Eo values: [BrO3] - → Br- Eo = +0.61 V [BrO]- → Br- Eo = +0.76 V What is the value of Eo for the reduction of [BrO3] - to [BrO]- ? Correct Answer: +0.54 V 19. Which one of the following is a disproportionation reaction? 6
Correct Answer:Cl2+2[OHTCr+[OCI]'+H2O 20.In which one of the following reactions is at least one iodine atom oxidized? Correct Answer:2I2+S2OF22[2][SO3F] Part2 1.(a)What is the collective name for the group 17elements?(b)Write down.inorder. the names and symbols of these elements,check your answer by reference to the first two pages of this chapter.(c)Give a general notation showing the ground state electronic configuration of each element. 2.(a)Write equations to show the reactions involved in the extraction of Bra and I from brines.(b)What reactions occur in the Downs process,and why must the products of the process be kept apart?(c)In the electrolysis cell used for the industrial preparation of F2,a diaphragm is used to separate the products.Give an equation for the reaction that would occur in the absence of the diaphragm and describe the nature of the reaction. 3.Describe in outline how you would attempt: (a)to determine the equilibrium constant and standard enthalpy change for the aqueous solution reaction: Cl2 +H2O=HCI+HOCI (b)to show that the oxide O(reported to be formed reaction between I2 and O3) reacts with water according to the reaction: I4O+9H20→"18HIO3+2 (c)to show that when alkali metal atoms and Cl interact in a solidified noble gas matrix at very low temperatures,the ion[Cl is formed. 4.Discuss the interpretation of each of the following observations: (a)Although the hydrogen bonding in HF is stronger than that in H2O,water has much the higher boiling point
Correct Answer: Cl2 + 2[OH]- → Cl- + [OCl]- + H2O 20. In which one of the following reactions is at least one iodine atom oxidized? Correct Answer: 2I2 + S2O6F2 → 2[I2][SO3F] Part 2 1. (a) What is the collective name for the group 17 elements? (b) Write down, in order, the names and symbols of these elements; check your answer by reference to the first two pages of this chapter. (c) Give a general notation showing the ground state electronic configuration of each element. 2. (a) Write equations to show the reactions involved in the extraction of Br2 and I2 from brines. (b) What reactions occur in the Downs process, and why must the products of the process be kept apart? (c) In the electrolysis cell used for the industrial preparation of F2, a diaphragm is used to separate the products. Give an equation for the reaction that would occur in the absence of the diaphragm and describe the nature of the reaction. 3. Describe in outline how you would attempt: (a) to determine the equilibrium constant and standard enthalpy change for the aqueous solution reaction: Cl2 + H2O＝HCl＋HOCl (b) to show that the oxide I4O9 (reported to be formed reaction between I2 and O3) reacts with water according to the reaction: I4O9＋9H2O →" 18HIO3 ＋I2 (c) to show that when alkali metal atoms and Cl2 interact in a solidified noble gas matrix at very low temperatures, the ion[Cl2] - is formed. 4. Discuss the interpretation of each of the following observations: (a) Although the hydrogen bonding in HF is stronger than that in H2O, water has much the higher boiling point. 7
(b)Silver chloride and silver iodide are soluble in saturated aqueous KI,but insoluble in saturated aqueous KCI. 5.(a)What is the collective name for the group 18 elements? (b)Write down,in order,the names and symbols of these elements;check your answer by reference to the first page of this chapter. (c)What common feature does the ground state electronic configuration of each element possess? 6.Construct MO diagrams for He2 and [Hez]and rationalize why the former is not known but the latter may be detected. 7.Why is XeCl2 likely to be much less stable than XeF2? 8.Suggest products for the following reactions(which are not necessarily balanced on the left-hand sides) (a)CsF+XeF4→ (b)SiO2+XeOF4-→ (c)XeF2+sbFs→ (dXeF6+IOH→ (e)Krf2+H,0→ Part2 (1)In group 18,He is unique because: A)it does not have an octet configuration in its ground state B)it has a higher reactivity than the other noble gases C)it forms a stable salt containing the [He]ion D)it has a long liquid range (2)First ionization energies(IEl)and van der Waals radii (rv)for the noble gases
(b) Silver chloride and silver iodide are soluble in saturated aqueous KI, but insoluble in saturated aqueous KCl. 5. (a) What is the collective name for the group 18 elements? (b) Write down, in order, the names and symbols of these elements; check your answer by reference to the first page of this chapter. (c) What common feature does the ground state electronic configuration of each element possess? 6.Construct MO diagrams for He2 and [He2] + and rationalize why the former is not known but the latter may be detected. 7.Why is XeCl2 likely to be much less stable than XeF2? 8. Suggest products for the following reactions (which are not necessarily balanced on the left-hand sides): (a) CsF + XeF4 → (b) SiO2 + XeOF4→ (c) XeF2 +SbF5 → (d) XeF6+ [OH]- → (e) KrF2 + H2O→ Part 2 (1) In group 18, He is unique because: A) it does not have an octet configuration in its ground state B) it has a higher reactivity than the other noble gases C) it forms a stable salt containing the [He2] + ion D) it has a long liquid range (2) First ionization energies (IE1) and van der Waals radii (rv) for the noble gases 8
follow the trends: A)IE:He Ne Ar>Kr>Xe:rv:He>Ne>Ar>Kr>Xe B)IE:He Kr>Xe C)IE:He Ne Ar>Kr>Xe;rv:He Ne <Ar<Kr Xe D)IE He <Ne <Ar<Kr Xe:rv:He <Ne <Ar Kr Xe (3)The xenon fluorides XeF2,XeF4 and XeF6 A)are all gases at 298 K B)are all thermodynamically unstable with respect to Xe and F2 C)all react with water,but not at the same rate D)all react with SiOz at 298 K (4)Which reaction is the least likely to occur? A)2XeF2+AsFs-[Xe2F3l[AsF6] B)XeF2+KF一KXeF] C)XeF+MeaNF-[MeN][XeFs] D)XeF6+2NaF-Na2[XeFs] (5)Match the formula to the point group.Which is incorrect for a molecular species? A)XeF4;Dan B)KrF2;D.h C)XeO4;Ta D)XeF:Op (6)Which statement is correct? A)Solid state KrF2 and XeF2 are isomorphous B)XeO;is highly explosive C)[XeFs is isoelectronic with IFs D)At pH 0,HXeO is a powerful oxidizing agent,but is less powerful than [MnO
follow the trends: A) IE1: He > Ne > Ar > Kr > Xe; rv: He > Ne > Ar > Kr > Xe B) IE1: He Ne > Ar > Kr > Xe C) IE1: He > Ne > Ar > Kr > Xe; rv: He < Ne < Ar < Kr < Xe D) IE1: He < Ne < Ar < Kr < Xe; rv: He < Ne < Ar < Kr < Xe (3) The xenon fluorides XeF2, XeF4 and XeF6: A) are all gases at 298 K B) are all thermodynamically unstable with respect to Xe and F2 C) all react with water, but not at the same rate D) all react with SiO2 at 298 K (4) Which reaction is the least likely to occur? A) 2XeF2 + AsF5 → [Xe2F3][AsF6] B) XeF2 + KF → K[XeF3] C) XeF4 + Me4NF → [Me4N][XeF5] D) XeF6 + 2NaF → Na2[XeF8] (5) Match the formula to the point group. Which is incorrect for a molecular species? A) XeF4; D4h B) KrF2; D∞h C) XeO4; Td D) XeF6; Oh (6) Which statement is correct? A) Solid state KrF2 and XeF2 are isomorphous B) XeO3 is highly explosive C) [XeF5] – is isoelectronic with IF5 D) At pH 0, H4XeO6 is a powerful oxidizing agent, but is less powerful than [MnO4] – 9
(7)The chemistry of xenon continues to grow,but which statement is incorrect? A)Compounds containing Xe-C bonds are known B)The [Xe2]ion has been established C)Stable xenon dihalides are known for X=F,Cl and Br D)Xe-N bond formation has been established (8)For which two compounds are their formations from their elements endothermic processes? A)XeO3 and XeOa B)XeF2 and XeFa C)XeF2 and XeFs D)XeF4 and XeOF2 (9)Match the shape to the formula.Which pairing is incorrect? A)[XeF厂；pentagonal planar B)XeO3:trigonal planar C)XeF;square planar D)[XeF3];T-shaped (10)Which classification is correct? A)XeF2 is a fluoride donor B)XeF is a fluoride acceptor and but not a fluoride donor C)AsFs donates fluoride ions to XeFn D)SbFs is a fluoride acceptor and always forms [SbF (11)Which structures for XeO;and XeF are consistent with the VSEPR model? A)XeO3,trigonal pyramidal:XeF.square planar B)XeO3,trigonal planar,XeFsquare planar C)XeO,trigonal pyramidal;XeF,tetrahedral
(7) The chemistry of xenon continues to grow, but which statement is incorrect? A) Compounds containing Xe–C bonds are known B) The [Xe2] + ion has been established C) Stable xenon dihalides are known for X = F, Cl and Br D) Xe–N bond formation has been established (8) For which two compounds are their formations from their elements endothermic processes? A) XeO3 and XeO4 B) XeF2 and XeF4 C) XeF2 and XeF6 D) XeF4 and XeOF2 (9) Match the shape to the formula. Which pairing is incorrect? A) [XeF5] – ; pentagonal planar B) XeO3; trigonal planar C) XeF4; square planar D) [XeF3] + ; T-shaped (10) Which classification is correct? A) XeF2 is a fluoride donor B) XeF6 is a fluoride acceptor and but not a fluoride donor C) AsF5 donates fluoride ions to XeFn D) SbF5 is a fluoride acceptor and always forms [SbF6] – (11) Which structures for XeO3 and XeF4 are consistent with the VSEPR model? A) XeO3, trigonal pyramidal; XeF4, square planar B) XeO3, trigonal planar; XeF4, square planar C) XeO3, trigonal pyramidal; XeF4, tetrahedral 10