Ch.6 - Ionic Compounds: Periodic Trends and Bonding Theory
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- Cesium has the smallest ionization energy of all elements (376 kJ/mol), and chlorine has the most negative electron affinity 1-349 kJ/mol2. Will a cesium atom transfer an electron to a chlorine atom to form isolated Cs+1g2 and Cl-1g2 ions? Explain.
Problem 81
- How does electron shielding in multielectron atoms give rise to energy differences among 3s, 3p, and 3d orbitals?
Problem 95
- Many early chemists noted a diagonal relationship among ele-ments in the periodic table, whereby a given element is some-times more similar to the element below and to the right than it is to the element directly below. Lithium is more similar to magnesium than to sodium, for example, and boron is more similar to silicon than to aluminum. Use your knowledge about the periodic trends of such properties as atomic radii and Zeff to explain the existence of diagonal relationships.
Problem 100
- Heating elemental cesium and platinum together for two days at 973 K gives a dark red ionic compound that is 57.67% Cs and 42.33% Pt. (c) What are the charge and electron configuration of the platinum ion?
Problem 101
- Consider the electronic structure of the element bismuth. (d) Would you expect element 115 to have an ionization ene-rgy greater than, equal to, or less than that of bismuth? Explain.
Problem 103
- Iron is commonly found as Fe, Fe2+, and Fe3+. (a) Write electron configurations for each of the three. (d) The third ionization energy of Ru is less than the third ionization energy of Fe. Explain.
Problem 104
Problem 104b
Iron is commonly found as Fe, Fe2+, and Fe3+. (b) What are the n and l quantum numbers of the electron removed on going from Fe2+ to Fe3+?
Problem 104c
Iron is commonly found as Fe, Fe2++, and Fe3+. (c) The third ionization energy of Fe is Ei3 = +2952 kJ/mol. What is the longest wavelength of light that could ionize Fe2+(g) to Fe3+(g)?
- The ionization energy of an atom can be measured by photo-electron spectroscopy, in which light of wavelength l is directed at an atom, causing an electron to be ejected. The kinetic energy of the ejected electron 1EK2 is measured by determining its velocity, v since EK = 1/2 mv2. The Ei is then calculated using the relationship that the energy of the inci-dent light equals the sum of Ei plus EK. (a) What is the ionization energy of rubidium atoms in kilo-joules per mole if light with l = 58.4 nm produces elec-trons with a velocity of 2.450 * 106m/s? (The mass of an electron is 9.109 * 10-31 kg.)
Problem 105
- Take a guess. What do you think is a likely ground-state electron configuration for the sodium ion, Na+, formed by loss of an electron from a neutral sodium atom?
Problem 114
- Order the following atoms according to increasing atomic radius: S, F, O.
Problem 120
- One method for calculating Zeff is to use the equation
Problem 129
where E is the energy necessary to remove an electron from an atom and n is the principal quantum number of the elec-tron. Use this equation to calculate Zeff values for the highest-energy electrons in potassium (E = 418.8 kJ/mol) and krypton (E = 1350.7 kJ/mol).
- At 0 °C, the density of liquid water is 0.9998 g/mL and the value of Kw is 1.14 * 10-15. What fraction of the molecules in liquid water are dissociated at 0 °C? What is the percent dissociation at 0 °C? What is the pH of a neutral solution at 0 °C?
Problem 144