Standard = 1.014.
2. One gram of an ore contained 0.307 gram of ferrous iron and 0.655
gram of total iron. The iron existing as oxide, what are the percentages
of ferrous oxide (FeO) and ferric oxide (Fe_{2}O_{3}) in the ore?
3. One gram of brown iron ore dissolved in hydrochloric acid required
59.2 c.c. of stannous chloride (standard = 0.930). Another gram
dissolved in acid and titrated with "permanganate" required 8.2 c.c.
(standard = 0.4951). Calculate the percentages of ferrous, ferric, and
total iron.
4. Another gram of the same ore, roasted, dissolved and titrated with
stannous chloride, required 63.5 c.c. To what extent does this result
confirm the others?
5. Two grams of a metal were dissolved and diluted to 100 c.c. Five c.c.
were taken for a colorimetric determination, and required 4.5 c.c. of
the standard ferric chloride solution. What is the percentage of iron in
the metal?
NICKEL.
Nickel and cobalt are closely related in their chemical properties, and
may best be considered together. Nickel is the commoner of the two, and
is met with in commerce alloyed with copper and zinc as German silver;
as also in the coinage of the United States and on the Continent. It is
used for plating polished iron and steel goods, forming a coating little
liable to rust and taking a good polish.
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