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Question
What chemical equation represents the best method for obtaining pure chromium?
A) FeCr2O4(s) + 4 C(s) + heat -> Fe(s) + 2 Cr(s) + 4 CO(g)
B) Cr2O3(s) + 2 Al(s) + heat -> 2 Cr(s) + Al2O3(s)
C) Cr2O3(s) + 2 Fe(s) + heat -> Fe2O3(s) + 2 Cr(s)
D) Cr2+(aq) + H2(g) -> Cr(s) + 2 H+(aq)
Answer
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Related questions
Q:
In the following picture of an oxide, darkly-shaded spheres represent oxygen atoms or ions and lightly-shaded spheres represent atoms or ions of a third-row element in its highest oxidation state. Tell whether the oxide is covalent or ionic and whether the oxide is acidic or basic. A) covalent and acidic
B) covalent and basic
C) ionic and acidic
D) ionic and basic
Q:
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B) silicon and oxygen form better σ bonds than carbon and oxygen, so Si-O single bonds are stronger than C-O single bonds.
C) carbon and oxygen form better π bonds than silicon and oxygen, so C=O double bonds are stronger than Si=O double bonds.
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Q:
Which element shown on the periodic table above forms an interstitial binary hydride with the formula MXx?
A) element A
B) element B
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B) element B
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Q:
When 3.600 grams of anhydrous magnesium chloride were exposed to moist air, water was absorbed by the sample. If the resulting hydrated compound has a mass of 4.962 grams, what is the chemical formula of the hydrate?
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C) CoCl2 6 H2O
D) Cu(OH)2
Q:
Indicate the coefficient in front of H2O2 when the following redox equation is balanced in an acidic medium.H2O2(aq) + MnO4-(aq) -> O2(g) + Mn2+(aq)A) 2B) 3C) 5D) 7
Q:
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B) H2O2
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Q:
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Q:
Which of the following is a peroxide?
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C) a superoxide.
D) an oxide and a superoxide.
Q:
Which of the following oxides has the highest melting point?
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Q:
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A) Si
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Which element most readily forms nonstoichiometric hydrides?
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Which transition metal hydride is commonly used in the purification of hydrogen gas?
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Q:
Covalent hydrides of the type MH3 are likely to form with elements of what group?
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Q:
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Q:
The bright colors of anodized titanium are due toA) electrodeposition of organic dyes on the titanium surface.B) the formation of a titanium alloy with chromium and copper.C) iridescence involving the semitransparent outer layer of TiO2.D) trapping of organic dye molecules in a spongy TiO2 matrix.
Q:
Chromium can be electroplated from an aqueous solution containing sulfuric acid and chromic acid, H2CrO4. What current is required to deposit chromium at a rate of 1.25 g/min?
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B) 38.7 A
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D) 232 A
Q:
How many grams of chromium metal are plated out when a constant current of 8.00 A is passed through an aqueous solution containing Cr3+ ions for 40.0 minutes?
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Q:
The electrolysis of an aqueous solution of NS produces oxygen at the anode according to the following equation:Calculate the volume of at STP that is produced by the passage of 3.00 A through this solution for 150 minutes.A) 1.57 LB) 0.0261 LC) 6.28 LD) 0.0700 L
Q:
O2(g) + 4 H+(aq) + 4 e--> 2 H2O(l) E = +1.23 VI2(s) + 2 e- -> 2 I-(aq) E = +0.54 V2 H2O(l) + 2 e- -> H2(g) + 2 OH-(aq) E = -0.83 VMg2+(aq) + 2 e- -> Mg(s) E = -2.37 VBased on the data above, electrolysis of an aqueous solution of MgI2, with inert electrodes, is expected to produceA) Mg at the cathode and I2 at the anode.B) H2 at the cathode and I2 at the anode.C) Mg at the cathode and O2 at the anode.D) H2 at the cathode and O2 at the anode.
Q:
A steel pipe can be protected from corrosion by attaching the pipe to a piece of magnesium because
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B) magnesium is more easily oxidized than iron.
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D) magnesium and steel form a corrosion resistant alloy.
Q:
Which of the following statements concerning the rusting of iron is false?
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B) The metal is reduced.
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Q:
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