T2-1P1 [187 marks] 1. How many protons, neutrons and electrons are present in each atom of 31 P? 2. What is the atomic number of a neutral atom which has 51 neutrons and 40 electrons? A. 40 B. 51 C. 91 D. 131 3. The table below shows the number of protons, neutrons and electrons present in five species. Which two species are isotopes of the same element? A. X and W B. Y and Z C. Z and W D. W and Q
4. What is the relative atomic mass of an element with the following mass spectrum? A. 24 B. 25 C. 26 D. 27 5a. Strontium exists as four naturally-occurring isotopes. Calculate the relative atomic mass of strontium to two decimal places from the following data. The graph of the first ionization energy plotted against atomic number for the first twenty elements shows periodicity. 5b. Define the term first ionization energy and state what is meant by the term periodicity. 5c. State the electron arrangement of argon and explain why the noble gases, helium, neon and argon show the highest first ionization [3 marks] energies for their respective periods. 5d. A graph of atomic radius plotted against atomic number shows that the atomic radius decreases across a period. Explain why chlorine has a smaller atomic radius than sodium. 5e. Explain why a sulfide ion, S 2, is larger than a chloride ion, Cl. 5f. Explain why the melting points of the Group 1 metals (Li Cs) decrease down the group whereas the melting points of the Group 7 elements (F I) increase down the group. [3 marks]
6a. Define the term isotopes. 6b. A sample of silicon contains three isotopes. Calculate the relative atomic mass of silicon using this data. 6c. Describe the structure and bonding in silicon dioxide and carbon dioxide. [4 marks] 6d. Draw the Lewis structure of NH3, state its shape and deduce and explain the H N H bond angle in NH 3. [4 marks] 6e. The graph below shows the boiling points of the hydrides of group 5. Discuss the variation in the boiling points. [4 marks] 6f. Explain, using diagrams, why CO and NO 2 are polar molecules but CO 2 is a non-polar molecule. [5 marks] 7. Which statement about the species 63 Cu 2+ and Cu + is correct? A. Both species have the same number of protons. B. Both species have the same number of electrons. C. Both species have the same number of neutrons. D. Both species have the same electron arrangement. 8. Which statement about the isotopes of an element is correct? A. They have the same mass number. B. They have a different atomic number. C. They have the same chemical properties. D. They are located in different places in the periodic table. 9. 31 How many electrons does the ion 15 P3 contain? A. 12 B. 15 C. 16 D. 18
Iron has three main naturally occurring isotopes which can be investigated using a mass spectrometer. A sample of iron has the following isotopic composition by mass. 10a. Calculate the relative atomic mass of iron based on this data, giving your answer to two decimal places. 10b. Calculate the number of electrons in the ion 56 Fe 2+. Describe the bonding in iron and explain the electrical conductivity and malleability of the metal. 10c. [4 marks] 11a. The relative atomic mass of naturally occurring copper is 63.55. Calculate the abundances of 63 Cu and 65 Cu in naturally occurring copper.
The isotopes of some elements are radioactive. State a radioisotope used in medicine. 11b. State a balanced equation for the reaction of sodium with water. Include state symbols. 11c. With reference to electronic arrangements, suggest why the reaction between rubidium and water is more vigorous than that 11d. between sodium and water. Describe and explain what you will see if chlorine gas is bubbled through a solution of 11e. [3 marks] (i) (ii) potassium iodide. potassium fluoride. 12. A sample of zinc has the following composition: What is the relative atomic mass of the zinc in this sample? A. 64.5 B. 65.0 C. 65.9 D. 66.4 13. Which quantities are the same for all atoms of chlorine? I. Number of protons II. III. Number of neutrons Number of electrons A. I and II only B. I and III only C. II and III only D. I, II and III 14. Which statement about the numbers of protons, electrons and neutrons in an atom is always correct? A. The number of neutrons minus the number of electrons is zero. B. The number of protons plus the number of neutrons equals the number of electrons. C. The number of protons equals the number of electrons. D. The number of neutrons equals the number of protons.
15. Consider the relative abundance of the isotopes of element X. What is the relative atomic mass of X? A. 24 B. 25 C. Between 24 and 25 D. Between 25 and 26 16. Which statements about the isotopes of chlorine, 35 17 Cl and 37 17 Cl, are correct? I. They have the same chemical properties. II. III. They have the same atomic number. They have the same physical properties. A. I and II only B. I and III only C. II and III only D. I, II and III Isotopes are atoms of the same element with different mass numbers. Two isotopes of cobalt are Co-59 and Co-60. 17. Deduce the missing information and complete the following table. 18a. Explain why the relative atomic mass of argon is greater than the relative atomic mass of potassium, even though the atomic number of potassium is greater than the atomic number of argon. 18b. Deduce the numbers of protons and electrons in the K + ion.
19a. Explain why the relative atomic mass of cobalt is greater than the relative atomic mass of nickel, even though the atomic number of nickel is greater than the atomic number of cobalt. 19b. Deduce the numbers of protons and electrons in the ion Co 2+. 19c. Deduce the electron configuration for the ion Co 2+. Carbon and silicon belong to the same group of the periodic table. 20a. State the period numbers of both carbon and silicon.
20b. Describe and compare three features of the structure and bonding in the three allotropes of carbon: diamond, graphite and C 60 fullerene. [6 marks] Both silicon and carbon form oxides. 20c. Draw the Lewis structure of CO 2 and predict its shape and bond angle.
20d. Describe the structure and bonding in SiO 2. Explain why silicon dioxide is a solid and carbon dioxide is a gas at room temperature. 20e. 20f. Describe the bonding within the carbon monoxide molecule.
Silicon has three stable isotopes, 28 Si, and. The heaviest isotope,, has a percentage abundance of 3.1%. Calculate 20g. 29 Si 30 Si 30 Si the percentage abundance of the lightest isotope to one decimal place. The element antimony, Sb, is usually found in nature as its sulfide ore, stibnite, Sb 2 S 3. This ore was used two thousand years ago by ancient Egyptian women as a cosmetic to darken their eyes and eyelashes. Calculate the percentage by mass of antimony in a sample of pure stibnite. State your answer to four significant figures. 21a. Antimony contains two stable isotopes, 121Sb and 123 Sb. The relative atomic mass of antimony is given in Table 5 of the Data Booklet. 21b. Calculate the percentage of each isotope in pure antimony. State your answers to three significant figures. 21c. State the number of neutrons present in an atom of 121Sb.
Rubidium contains two stable isotopes, 85 Rb and 87 Rb. The relative atomic mass of rubidium is given in Table 5 of the Data Booklet. Calculate the percentage of each isotope in pure rubidium. State your answers to three significant figures. 22a. 22b. State the number of electrons and the number of neutrons present in an atom of 87 Rb. Number of electrons: Number of neutrons: 23. What is the correct number of each particle in an oxygen ion, 18 O 2? 24. Which subatomic particles are located in the nucleus of an atom? A. Protons and electrons B. Neutrons and electrons C. Protons and neutrons D. Protons, neutrons and electrons Lithium and boron are elements in period 2 of the periodic table. Lithium occurs in group 1 (the alkali metals) and boron occurs in group 3. Isotopes exist for both elements. 25a. (i) Define the terms atomic number, mass number and isotopes of an element. [10 marks] Atomic number: Mass number:
Isotopes of an element: (ii) Distinguish between the terms group and period. (iii) Deduce the electron arrangements of the lithium ion, Li +, and the boron atom, B. Li + : B: (iv) Naturally occurring boron exists as two isotopes with mass numbers of 10 and 11. Calculate the percentage abundance of the lighter isotope, using this information and the relative atomic mass of boron in Table 5 of the Data Booklet. v) Lithium exists as two isotopes with mass numbers of 6 and 7. Deduce the number of protons, electrons and neutrons for each isotope.
Every element has its own unique line emission spectrum. (i) 25b. Distinguish between a continuous spectrum and a line spectrum. [6 marks] (ii) Draw a diagram to show the electron transitions between energy levels in a hydrogen atom that are responsible for the two series of lines in the ultraviolet and visible regions of the spectrum. Label your diagram to show three transitions for each series.
(i) 25c. (ii) iii) Explain why metals are good conductors of electricity and why they are malleable. Iron is described as a transition metal. Identify the two most common ions of iron. Deduce the chemical formulas of lithium oxide and iron(ii) oxide. [4 marks] Lithium oxide: Iron(II) oxide: 131 I is a radioactive isotope of iodine. 26a. Define the term isotope. Determine the number of neutrons in one atom of iodine-131. 26b.
27. What are the numbers of neutrons and electrons in the iodine ion, 125 I +? 28. What are the numbers of neutrons and electrons in the iodine ion, 125 I +? 29. Which statements about the isotopes of an element are correct? I. They have the same chemical properties. II. III. They have different physical properties. They have the same number of protons and electrons. A. I and II only B. I and III only C. II and III only D. I, II and III 30. Which is an isotope of 24Mg? A. 24 11 Na B. 24 21 Mg2+ C. D. 26 12 Mg 22 10Ne 2-methylbutan-2-ol, (CH 3 ) 2 C(OH)CH 2 CH 3, is a liquid with a smell of camphor that was formerly used as a sedative. One way of producing it starts with 2-methylbut-2-ene. Draw the structure of 2-methylbut-2-ene. 31a.
31b. State the other substances required to convert 2-methylbut-2-ene to 2-methylbutan-2-ol. Explain whether you would expect 2-methylbutan-2-ol to react with acidified potassium dichromate(vi). 31c. 31d. Explain why 2-methylbut-2-ene is less soluble in water than 2-methylbutan-2-ol. 2-chloro-2-methylbutane contains some molecules with a molar mass of approximately 106 g mol 1 and some with a molar mass of approximately 108 g mol 1. 31e. Outline why there are molecules with different molar masses. 2-methylbutan-2-ol, (CH 3 ) 2 C(OH)CH 2 CH 3, is a liquid with a smell of camphor that was formerly used as a sedative. One way of producing it starts with 2-methylbut-2-ene. State the other substances required to convert 2-methylbut-2-ene to 2-methylbutan-2-ol. 32a.
Explain whether you would expect 2-methylbutan-2-ol to react with acidified potassium dichromate(vi). 32b. As well as 2-methylbutan-2-ol, the reaction also produces a small quantity of an optically active isomer, X. 32c. State what is meant by optical activity. State what optical activity indicates about the structure of the molecule. 32d. 32e. Optical activity can be detected using a polarimeter. Explain how this works. [3 marks]
Deduce the structural formula of X. 32f. 32g. Explain why 2-methylbut-2-ene is less soluble in water than 2-methylbutan-2-ol.
2-methylbutan-2-ol can also be produced by the hydrolysis of 2-chloro-2-methylbutane, (CH 3 ) 2 CClC 2 H 5, with aqueous sodium hydroxide. Explain the mechanism of this reaction using curly arrows to represent the movement of electron pairs. 32h. [4 marks] 32i. State the rate expression for this reaction and the units of the rate constant. Suggest why, for some other halogenoalkanes, this hydrolysis is much more effective in alkaline rather than in neutral conditions. 32j.
2-chloro-2-methylbutane contains some molecules with a molar mass of approximately 106 g mol 1 and some with a molar mass of approximately 108 g mol 1. Outline why there are molecules with different molar masses. 32k. 2-chloro-2-methylbutane can also be converted into compound Z by a two-stage reaction via compound Y: Draw the structure of Y. 32l. 32m. State the reagent and any catalyst required for both the formation of Y and the conversion of Y into Z. [3 marks] Formation of Y: Conversion of Y into Z:
The element boron has two naturally occurring isotopes, 10 B and 11B. Define the term isotopes of an element. 33a. 33b. Calculate the percentage abundance of each isotope, given that the relative atomic mass of B is 10.81. 33c. Deduce the Lewis structures of NH 3 and BF 3. NH3 BF3 33d. Describe how covalent bonds are formed.
Compare the shapes of the two molecules and explain the difference using valence shell electron pair repulsion theory (VSEPR). 33e. [4 marks] 33f. Predict and explain whether the molecules NH 3 and BF 3 are polar molecules. Chlorine occurs in Group 7, the halogens. Two stable isotopes of chlorine are 35 Cl and 37 Cl with mass numbers 35 and 37 respectively. Define the term isotopes of an element. 34a. 35 37
34b. Calculate the number of protons, neutrons and electrons in the isotopes 35Cl and 37Cl. Using the mass numbers of the two isotopes and the relative atomic mass of chlorine from Table 5 of the Data Booklet, determine 34c. the percentage abundance of each isotope. Percentage abundance 35Cl: Percentage abundance 37Cl: Chlorine has an electronegativity value of 3.2 on the Pauling scale. Define the term electronegativity. 34d.
Using Table 7 of the Data Booklet, explain the trends in electronegativity values of the Group 7 elements from F to I. 34e. 34f. State the balanced chemical equation for the reaction of potassium bromide, KBr(aq), with chlorine, Cl (aq). 2 Describe the colour change likely to be observed in this reaction. 34g.
Chloroethene, H2C=CHCl, the monomer used in the polymerization reaction in the manufacture of the polymer poly(chloroethene), PVC, can be synthesized in the following two-stage reaction pathway. Stage 1: Stage 2: C 2 H 4 (g) + Cl 2 (g) ClCH 2 CH 2 Cl(g) ClCH 2 CH 2 Cl(g) + HC=CHCl(g) + HCl(g) Determine the enthalpy change, ΔH, in kj mol, for stage 1 using average bond enthalpy data from Table 10 of the Data 34h. 1 Booklet. [3 marks] State whether the reaction given in stage 1 is exothermic or endothermic. 34i. Draw the structure of poly(chloroethene) showing two repeating units. 34j.
34k. Suggest why monomers are often gases or volatile liquids whereas polymers are solids. 35. Which ion will show the least deflection in a mass spectrometer? A. B. C. D. 35 Cl + 35 Cl 2+ 35 Cl 35 Cl + 35 Cl 37 Cl + 36. What does 52 represent? 24 X A. An isotope of Te with 24 neutrons B. An isotope of Te with 24 electrons C. An isotope of Cr with 28 protons D. An isotope of Cr with 28 neutrons 37. Which species would be deflected most in a mass spectrometer? A. 24Mg 2+ B. C. D. 24Mg + 25 Mg 2+ 25 Mg + International Baccalaureate Organization 2017 International Baccalaureate - Baccalauréat International - Bachillerato Internacional Printed for BLUPS