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List Of Contents | Contents of An Introduction to Chemical Science
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put it into a small flask provided with a thistle-tube and a
delivery-tube. Cover the Zn with water, and introduce through the
thistle-tube measured quantities of HCl, a few cubic centimeters
at a time. Collect the H over water in large flasks, observing
the same directions as in removing O. Weigh the water, compute
the volume of the gas, reduce it to the standard, and obtain the
weight, as before. Should any Zn or other solid substance be
left, pour off the water or filter it, weigh the dry residue, and
deduct its weight from that of the Zn originally taken. Suppose
the residue to weigh 0.5g. Make and solve the proportion from the
equation:-


Zn + 2HCl = ZnCl2 + 2H.
65 	             2.
4.5	             x.


Compute the percentage of errcr, as in the case of O. If the
purity of the HCl be known, i.e. the weight of HCl gas in one
cubic centimeter of the liquid, a proportion can be made between
HCl and H, provided no free HCl is left in the flask. State any
liabilities to error in this experiment.

PROBLEMS.

(1) A gas occupies 2000cc.when the barometer stands
750mm. What volume will it fill at 760mm?

(2) At 750mm my volume of O is 4 1/2 liters. What will it be at
730mm?

(3) At 825mm?

(4) At 200mm?

(5) Compute the volume of a gas at 70 degrees, which at 30
degrees is 150cc.

(6) At 0 degrees I have 3000cc.of O. What volume will it occupy
at 100 degrees?

(7) I fill a flask holding 2 litres with H. The thermometer
indicates 26 degrees, the barometer 762mm. What is the volume of
the gas at 0 degrees and 760mm?

If the volumes of gases vary as above, it is evident that their
vapor densities must vary inversely. A liter of H at 0 degrees
weighs 0.0896. What will a liter of H weigh at 273 degrees? At
273 degrees the one liter has be- come two liters, one of which
weighs 0.0448 (= 0.0896 / 2). The vapor density of a gas is
inversely proportional to the temperature. Also, the vapor
density is directly proportional to the pressure, since a liter
of any gas under a pressure of one atmosphere is reduced to half
a liter under two atmospheres.

PROBLEMS.

(1) Find the weight of a liter of O at 0 degrees; then compute the
weight of a liter at 27  degrees.

(2) Find the weight of 500cc.of N2O at 60 degrees.

(3) Of 200 cc. of CO at -5 degrees.

(4) A given volume of O weighs 0.25g at a pressure of 750mm; find
the weight of a like volume of O at 758mm.

APPENDIX.

INDIVIDUAL APPARATUS.

Each pupil should be provided with the apparatus given below, but in
cases where great economy must be exercised different pupils may, by
working at different times, use the same set. The author has selected
apparatus specially adapted, as to exact dimensions, quality, and cheap-
ness, for performing in the best way the experiments herein described,
and sets or separate pieces of this, together with other apparatus and
chemicals, can be had of the L.E. Knott Apparatus Co., 14 Ashburton
Place, Boston, to which firm teachers are referred for catalogs.

4 wide-mouthed bottles (horse-radish size), with corks.
1 soda-bottle.
4 pieces window-glass (3 in. sq.).
2 pieces thick glass tubing (20 in. long, 4 in. outside diam.).
1 glass stirring-rod.
1 glass funnel (2 1/2 in. wide, 60 degrees).
2 pieces glass tubing (12 in. long; 5/8 in. diam.).
1 porcelain evaporating-dish (3 in. wide).
1 asbestus paper and 1 fine wire gauze (3 in. sq.).
1 iron (or tin) plate.
1 pair forceps.
1 triangular file and 1 round file.
1 copper wire (15 in. long).
6 test-tubes, and corks to fit.
1 wooden test-tube holder.
1 flask with cork (200cc).
1 Bunsen burner (or alcohol lamp).
1 iron ring-stand.
1 piece rubber tubing (18 in. long,
3/8 in. inside diam.).
4 reagent bottles (250cc), HCl, HNO3, H2SO4, NH4OH.
1 pneumatic trough.

Wherever in this work "Bunsen burner" or "lamp" is mentioned, if
gas is not to be had, an alcohol lamp may be substituted.

GENERAL APPARATUS.

The following list includes apparatus needed for occasional
use:--

Metric rules (20 or 30cm long).
Scales with metric weights (1-200 g).
Metric graduates (25 or 50cc).
Filter papers.
Metric graduates (500cc).
Reagent bottles (250 and 500cc).
Mouth blowpipes.
Platinum wire and foil.
Mortars and pestles.
Test-tube racks.
Thistle-tubes.
Filter-stands.
Beakers.
Glass tubing (3/16 in., 1/4 in., and 1 in. outside).
Rubber tubing (1/8 in., and 3/8 in. inside).
Hessian crucibles.
Porcelain crucibles.
Electrolytic apparatus, including 2 or more Bunsen cells.
Ignition-tubes.
Steel glass-cutters.
Wire-cutters.
Calcium chloride tubes.
Water baths.
Thermometers.
Barometers, etc.

APPENDIX.

CHEMICALS.

The following estimate is for twenty pupils: -
Alcohol   1 pt
Alum  1 oz
Ammonium chloride  1/2 lb
Ammonium hydrate  1 lb
Ammonium nitrate.  1/2 lb
Antimony (powdered metallic) 1/2 oz.
Arsenic (powdered metallic) 1/2 oz.
Arsenic trioxide..... 1 oz.
Barium chloride..... 1 oz.
Barium nitrate..... 1 oz.
Beeswax....... 1 oz.
Bleaching-powder.... 1/4 lb.
Bone-black...... 1/2 lb.
Bromine....... 1/4 lb.
Calcium chloride.... 1 lb.
Calcium fluoride (powdered) 1 lb.
Cannel coal  1 lb
Carbon disulphide  1/4 lb
Chlorhydric acid  6 lb
Cochineal  1 oz
Copper (filings)  2 lb.
Copper nitrate  1 oz
Copper oxide  1/4 lb.
Ether (sulphuric)  1/4 lb
Ferrous sulphide  1 lb.
Ferrous sulphate  1/4 lb
Indigo  1/4 lb
Iodine  1 oz
Iron (filings or turnings)  1 lb.
Lead (sheet)  4 lb
Lead acetate  1 oz
Lead nitrate  1/4 lb
Litmus  1/2 oz
Litmus paper  3 sheets
Magnesium ribbon.... 3 ft.
Manganese dioxide.... 2 lb.
Mercurous nitrate.... 1/2 oz.
Nitric acid  3 lb.
Oxalic acid  1/4 lb
Phosphorus  1/4 lb
Potassium (metallic)  1/8 oz
Potassium bromide  1/4 lb.
Potassium dichromate  1/4 lb.
Potassium chlorate  2 lb.
Potassium hydrate  1/4 lb.
Potassium iodide  2 oz
Potassium nitrate  1/4 llb
Silver nitrate  1 oz.
Sodium  1/8 oz.
Sodium carbonate  1/4 lb
Sodium hydrate  1 lb.
Sodium nitrate  1/2 lb
Sodium silicate..... 1/2lb
Turkey red cloth.... 1/2yd
Sodium sulphate..... 1/4lb
Turpentine(spirits). 1/4lb
Sodium sulphide..... 1/4lb
Zinc(granulated).... 2lb
Sodium thiosulphate. 1/4lb
Zinc foil........... 3ft
Sulphur............. 2lb
Sulphuric acid...... 12lb

Additional Material

These substances are best obtained of local dealers.

Calcium carbonate(marble)..... 1lb
Molasses...................... 1pt
Calcium oxide(unslaked lime).. 1lb
Sodium chloride(fine)......... 1lb
Charcoal...................... 1lb
Sodium chloride(coarse)....... 1lb
Sheet lead.................... 4lb
Sugar......................... 1/2lb

FOR EXAMINATION

Those in capitals are most important

Rocks and Minerals.
ARGILLITE,
ARESENIC,
ARSENOPYRITE,
Barite,
CALCITE,
CASSITERITE,
CHALCOPYRITE,
CHALK,
CINNABAR,
COPPER (native),
Corundum,
Dolomite,
EMERY,
FELDSPAR,
Flint,
GALENITE,
GRANITE,
GRAPHITE,
GYPSUM,
HEMATITE,
Hornblende,
Jasper,
LIMONITE,
MAGNESITE,
MAGNETITE,
MALACHITE,
Meerschaum,
MICA,
OBSIDIAN,
Orpiment,
PYRITE,
QUARTZ,
Realgar,
SAND,
SERPENTINE,
SIDERITE,
SPHALERITE,
Talc,
ZINCITE

Metals and Alloys.

Aluminium,	Iron (cast),
Aluminium bronze.	Pewter,
Bell metal,	Solder,
Brass, 	Steel,
Bronze,	Type metal,
Copper,	Tin foil,
Galvanized iron,	Tin (bright plate and terne plate),
German silver, 	Zinc (sheet).
Iron (wrought)

Additional Compounds, for Examination:

Copper acetate,	Lead carbonate,
Copper arsenite,	Red lead,
Copper nitrate,	Magnesia alba,
Copper sulphate,	Smalt,
Lead dioxide,	Vermilion.
Lead protoxide,

TABLE OF SOLUTIONS.

Number of grams of solids to be dissolved in 500cc of water.

AgNO3.........		25	K2Al2(SO4)4......	50
BaCl2.........		50	KBr....                 25
Ba(N0 3)2........	30      K2Cr207........		50
CaClz.........          60	KI..........            25
Ca(OH)2......     saturated	KOH.......	        60
CaS04.......      saturated	NaICOS........	        50
CUC12		        50	NaOH		        60
Cu(N03).........	50	NalSl03.......    saturated
FeS04.........		50	NH,N03........		50
HgC12.........          30	Pb(C2H302)2......	50
HgN03..... 25 + 25 HN03		Pb(NOs)2.......	. 50


Other solutions....saturated.

Indigo solution (sulphindigotic acid) is prepared by heating for
several hours over a water bath, a mixture of ten parts of H 2SO4
with one of indigo, and, after letting it stand twenty-four
hours, adding twenty parts of water and filtering.



TEXTBOOK ADVERTISEMENTS THAT APPEARED IN THE ORIGINAL EDITION



INTRODUCTION TO CHEMICAL SCIENCE

By R.P. WILLIAMS, Instructor in Chemistry in the English High
School, Boston. l2mo. Cloth. 216 pages. By mail, 90 cents; for
introduction, 80 cents.

This work is strictly, but easily, inductive. The pupil is
stimulated by query and suggestion to observe important
phenomena, and to draw correct conclusions. The experiments are
illustrative, the apparatus is simple and easily made. The
nomenclature, symbols, and writing of equations are made
prominent features. In descriptive and theoretical chemistry, the
arrangement of subjects is believed to be especially superior in
that it presents, not a mere aggregation of facts, but the
science of chemistry. Brevity aud concentration, induction,
clearness, accuracy, and a legitimate regard for interest, are
leading characteristics. The treatment is full enough for any
high school or academy.

Though the method is an advanced one, it has been so simplified
that pupils experience no difficulty, but rather an added
interest, in following it.

The author himself has successfully employed this method in
classes so large that the simplest and most practical plan has
been a necessity.

Thomas C. Van Nuys, Professor of Chemistry, Indiana University,
Bloomington, Ind.:

"I consider it an excellent work for students entering upon the
study of chemistry."

C.F. Adams, Teacher of Science, High School, Detroit, Mich.:

"I have carried two classes through Williams's Chemistry. The
book has surpassed my highest expectations. It gives greater
satisfaction with each succeeding class."

J.W. Simmons, County Superintendent of Schools, Owosso, Mich.:

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