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- Which is more acidic? (a) Cr2O3 or CrO3 (b) N2O5 or N2O3 (c) SO2 or SO3
Problem 128
- Which is more basic? (a) CrO or Cr2O3 (b) SnO2 or SnO (c) As2O3 or As2O5
Problem 129
- Write a balanced net ionic equation for the reaction of each of the following oxides with water: (a) BaO (b) Cs2O (c) N2O5.
Problem 131
- Write a balanced net ionic equation for the reaction of the amphoteric oxide ZnO with aqueous sodium hydroxide. [The product is Zn(OH)4^2-.]
Problem 132
- Write a balanced net ionic equation for the reaction of the amphoteric oxide Ga2O3 with aqueous potassium hydroxide (KOH). [The product is Ga(OH)4-.]
Problem 133
Problem 134
Describe the structure of the sulfur molecules in:
(a) Rhombic sulfur (b) Monoclinic sulfur(c) Plastic sulfur (d) Liquid sulfur above 160 °C
- The viscosity of liquid sulfur increases sharply at about 160 °C and then decreases again above 200 °C. Explain.
Problem 135
- Write a balanced net ionic equation for each of the following reactions. (a) Zn(s) + dilute H2SO4(aq) → ? (b) BaSO3(s) + HCl(aq) → ? (c) Cu(s) + hot, concentrated H2SO4(l) → ? (d) H2S(aq) + I2(aq) → ?
Problem 136
- Write a balanced net ionic equation for each of the following reactions. (a) ZnS(s) + HCl(aq) → ? (b) H2S(aq) + Fe(NO3)3(aq) → ? (c) Fe(s) + dilute H2SO4(aq) → ? (d) BaO(s) + H2SO4(aq) → ?
Problem 137
Problem 138a
Account for each of the following observations.
(a) H2SO4 is a stronger acid than H2SO3.
Problem 138b
Account for each of the following observations.
b. SF4 exists, but OF4 does not.
- Account for each of the following observations: (a) Oxygen is more electronegative than sulfur. (b) Sulfur forms long Sn chains, but oxygen does not.
Problem 139
- (b) Why is the S8 ring nonplanar?
Problem 141
- Fuming sulfuric acid is formed when sulfur trioxide dissolves in anhydrous sulfuric acid to form H2S2O7. Propose a structure for H2S2O7, which contains an S - O - S linkage.
Problem 143
Problem 144
Little is known about the chemistry of astatine (At) from direct observation, but reasonable predictions can be made.
(a) Is astatine likely to be a gas, a liquid, or a solid?
- Why does chemical reactivity decrease from top to bottom in group 7A?
Problem 145
- The element bromine was first prepared by oxidation of aqueous potassium bromide with solid manganese(IV) oxide. Write a balanced net ionic equation for the reaction in an aqueous acidic solution. Mn2+ is also formed.
Problem 146
- The first preparation of chlorine was similar to the synthesis of elemental bromine (Problem 22.146). A later method entailed the reaction of hydrogen chloride and oxygen at 400 °C. Write a balanced equation for the reaction. (Water is also formed.)
Problem 147
- Reaction of titanium and chlorine at 300 °C yields a metal halide that is 25.25% Ti by mass. The melting point (124 °C) and boiling point (136 °C) of the halide suggest it is a molecular compound rather than an ionic one. (a) What are the formula and name of the compound, assuming the molecular formula is the same as the empirical formula? (b) Write the balanced equation for the reaction.
Problem 148
- Niobium reacts with fluorine at room temperature to give a solid binary compound that is 49.44% Nb by mass. (a) What is the empirical formula of the compound? (b) Write a balanced equation for the reaction.
Problem 149
Problem 149a,b
Niobium reacts with fluorine at room temperature to give a solid binary compound that is 49.44% Nb by mass. (a) What is the empirical formula of the compound? (b) Write a balanced equation for the reaction.
Problem 149c
Niobium reacts with fluorine at room temperature to give a solid binary compound that is 49.44% Nb by mass.
(c) The compound reacts with hydrogen to regenerate niobium. Write a balanced equation for the reaction.
- Write the formula for chlorous acid and indicate the oxidation state of the halogen.
Problem 151
- Write an electron-dot structure for each of the following molecules or ions and predict the geometrical structure: (a) HIO3 (b) ClO2- (c) HOCl (d) IO6^5-
Problem 152
- Write an electron-dot structure for each of the following molecules or ions, and predict the geometrical structure: (a) BrO4- (b) ClO3- (c) HIO4 (d) HOBr.
Problem 153
- Explain why acid strength increases in the order HClO 6 HClO2 6 HClO3 6 HClO4.
Problem 154
- Explain why acid strength increases in the order HIO < HBrO < HClO.
Problem 155
- Iodine forms the acid anhydride I2O5. Write a balanced equation for the reaction of this anhydride with water, and name the acid that is formed.
Problem 156
Problem 157
Chlorine reacts with molten sulfur to yield disulfur dichloride, a yellowish-red liquid. Propose a structure for disulfur dichloride.
- In the early 1960s, krypton was found to react with fluorine gas in an electrical discharge tube at -183 °C. The compound formed was KrF2. What are the oxidation states of Kr and F in this compound? What is the electron-dot structure and geometry?
Problem 158