Practice Quiz Chapter 22If you miss more than three, you should study more befor taking the on-line quiz.You may retake this test as many times as you like.
The ______________ process uses a boiling 30% sodium hydroxide solution to treat bauxite.
Bayer
Hall-Heroult
Dow
Frasch
Haber
Electrometallurgy uses _________________ to separate a metal from its ore.
solid phase chemical properties
electrical processes
thermal processes
aqueous chemical processes
molten salt processes
Transition elements from the right side of the periodic table are generally found as
sulfides because they tend to give up bonding electrons and form crystals with high lattice energies with sulfur.
sulfides because their electronegativities favor formation of covalent bonds with the polarizable sulfide anion.
oxides because they tend to give up bonding electrons and form crystals with high lattice energies with oxygen.
oxides because oxygen, with its high electronegativity, forms strong covalent bonds with them.
none of the above.
The alkali metals are isolated from non-aqueous systems. Why is this necessary?
The electrolysis of aqueous solutions of the alkali metals requires more energy than electrolysis of the molten salts.
The dissolved alkali earth halides are too reactive to be electrolyzed.
The aqueous metal ions are more difficult to reduce than water.
The reduction potentials of the alkali metals are more positive than the reduction potential of water.
The aqueous metal ions react violently with water.
Transition elements from the left side of the periodic table are generally found as
the uncombined elements, because they are noble metals.
In the commercial production of aluminum metal, the final stage involves the reaction2Al2O3(in molten Na3AlF6) + 3C(graphite) → 4Al(l) + 3CO2(g)Briefly outline the method and equipment with which the reaction is accomplished.
Which of the following elements is used in xerography?
titanium
germanium
chromium
selenium
xenon
Compared to the asbestos diaphragm-cell used in the chlor-alkali process, lista. one main advantage and one disadvantage of mercury cellsb. two important advantages of polymer membrane-cells
The most abundant element in the Earth's crust is
H
Fe
Al
Si
O
The leaching of gold can be represented by the equation4Au(s) + O2(s) + 8CN-(aq) + 2H2O(l) → 4Au(CN)2-(aq) + 4OH-(aq)In this reaction, identify the oxidant, the reductant and the oxidation numbers of the elements which change.
The process that selectively extracts a metal from its ore, by dissolving it, is called
roasting.
leaching.
smelting.
flotation.
hydration.
Sulfide ores are frequently treated by flotation in order to concentrate them.
The process of converting metal sulfides to metal oxides is called
sulfoxidation.
The Downs cell is used in the production of
copper.
hydrogen.
iron.
magnesium.
sodium.
In the industrial electrolysis of aqueous NaCl (the chlor-alkali process), the modern trend is toward use of cells incorporating polymer membranes to separate the anode and cathode solutions.
This is the end of the test. When you have completed all the questions and reviewed your answers, press the button below to grade the test.