Unit 1 Section C Summary HW Problems Pt. 3

#21:
a.
i. 68.3%
ii. 10%
iii. 6.83%

#22:
The percent composition is determined by using an element's molar mass, not the amount of atoms of it in a compound.

#23:
Oxidation is losing (electrons), reduction is gaining (electrons)

#24:
a. Au2+ + 2e- --> Au
b. V - 4e- --> V4+
c. Cu+ - e- --> Cu2+

#25:
a. Reduction
b. Oxidation
c. Reduction

#26:
a. Zinc because it lost electrons
b. Nickel because it gained electrons
c.  Zinc

#27:
a. Mercury because it lost electrons
b. Potassium because it gained electrons
c. Mercury

#28:
a. Al + Cr3+ -->  Al3+ + Cr
b. Mn2+ + Mg --> Mn + Mg2+

#29:
a. Electrometallurgy uses an electric current to supply electrons to metal ions, reducing them
b. Pyrometallurgy treats metals and their ores with thermal heat
c. Hydrometallurgy treats ores and other metal-containing materials with reactant in water solution

#30:
a. Electrometallurgy
b. Pyrometallurgy