SOLVED

51) The main source of titanium is: A) seawater B) rutile ore, TiO2 C) oxide ores D) TiS2 E) atmospheric gases 52) Choose the INCORRECT statement. A) Titanium is valued for its low density, high structural strength and corrosion resistance. B) Titanium chloride is the most widely used white pigment for paints. C) Chromium is often used to plate other metals for decorative purposes. D) Dichromate is Cr2O72-. E) Chromate is CrO42-. 53) Which of the following is amphoteric? A) V2O5 B) CrO C) Al(H2O)63+ D) Fe(H2O)63+ 54) Which of the following definitions is INCORRECT? A) amalgam: a solid solution or alloy containing mercury B) coinage metals: the transition elements of Group 11 (1B) C) galvanized iron: iron which has been electroplated with tin D) lanthanides: elements of atomic number 58 through 71 E) pig iron: slightly impure iron as obtained directly from the blast furnace 55) Which of the following forms a colorless aqueous solution? A) CuClO4 B) CoSO4 C) NiCl2 D) FeCl3 56) Order the following compounds from acidic to basic, with the most acidic on the left. CrO, Cr2O3, CrO3 A) CrO3 > Cr2O3 > CrO B) CrO3 > CrO > Cr2O3 C) Cr2O3 > CrO3 > CrO D) CrO > Cr2O3 > CrO3 57) Write the equation for the initial treatment of titanium ore. A) TiO2(s) + Cl2(g) + C(s) → TiCl2(g) + CO2(g) B) TiCl4(s) + 2 H2O(l) → TiO2(g) + HCl(g) C) TiO2(s) + 2 Cl2(g) + C(s) → TiCl4(g) + 2 CO(g) D) Ti(s) + 2 Cl2(g) → TiCl4(g) E) TiS(s) + 2H2O(l) → TiO2(g) + 2 H2S(g) 58) If a solution is prepared by dissolving 1.6 mol Na2CrO4 in 1.0 L of a buffer at pH 8.24, what will be [Cr2O72-] in the solution? The resultant equilibria are: HCrO4- ? H+ + CrO42- Ka = 3.2 × 10-7 2 HCrO4- ? Cr2O72-+ H2OK = 33 A) 9.9 × 10-5 M B) 2.9 × 10-28 M C) 8.9 × 10-9 M D) 8.6 × 102 M E) 2.8 × 10-2 M 59) An iron plate of 0.559 m2 surface area is to be chrome plated using a chromic acid-sulfuric acid plating bath. The anode and cathode half-equations are: Cathode: Cr2O72- + 14 H+ + 12 e- → 2 Cr + 7 H2OE° = 0.320 V Anode: 2 H2O → O2 + 4 H+ + 4 e-E° = 1.229 V Determine the minimum energy needed to produce a plating 0.115 mm thick on the iron plate. The density of chromium is 7.19 g/cm3. A) 526 kJ B) 780 kJ C) 1.05 × 103 kJ D) 4.68 × 103 kJ E) 9.36 × 103 kJ 60) MnO4- produces what manganese-containing species when used as an oxidizing agent in weakly basic solution? A) MnO42- B) Mn C) Mn2+ D) Mn2O3 E) MnO2