CHEMICAL CALCULATIONSF.Courtesy of Charles Roth toAntoine Laurent Lavoisier "It was left to Lavoisier transform a(1743-1794). tenet of Conservation of into a fruitful scientificphilosophical (Law Matter) prin- and to it to the of chemicalciple, apply interpretation phenomena." BERTHELOT, La Revolution Chimique.SERIESNEW-WORLD SCIENCE W'. RitchieEdited by John CHEMICAL CALCULATIONS PRESENTATION OF THE SOLUTION OFA SYSTEMATIC TYPE WITH IOOO CHEMICAL PROBLEMSPROBLEMS, ARRANGED PROGRESSIVELY ACCORDING TO LESSON ASSIGNMENTS BERNARD M.A.JAFFE,By Instructor in SchoolChemistry, Jamaica High New York City Tankers-on-Hudson New Tork y WORLD BOOK COMPANY 2126 Prairie Avenue, Chicago 1927WORLD BOOK COMPANY THE HOUSE OF APPLIED KNOWLEDGE Established W.1905 by Caspar Hodgson T YONKERS-ON NEW YORK --HUDSON, 2126 PRAIRIE CHICAGOAVENUE, textbooks intended to be used inChemistry high school and classesbeginning college havebeenfound many teachers to containby rather too few in the mathematicsproblems of the subject. Yet in examina-chemistry tions undergiven state as insupervision, New and in entrance examina-York, college tions three of tenperhaps questions out mathematical calculations. Itrequire was to thehands ofprimarily strengthen teachers a in some of theby overcoming deficiency basal texts in that this book ofchemistry Chemical Calculations was prepared NWSS : JCC-2 WorldCopyright 1926 by Book Company in Great BritainCopyright All rights reserved WONTED IN tr.S.A.PREFACE IN an ...
CHEMICAL CALCULATIONSF.Courtesy of Charles Roth
toAntoine Laurent Lavoisier "It was left to Lavoisier transform a(1743-1794).
tenet of Conservation of into a fruitful scientificphilosophical (Law Matter) prin-
and to it to the of chemicalciple, apply interpretation phenomena." BERTHELOT,
La Revolution Chimique.SERIESNEW-WORLD SCIENCE
W'. RitchieEdited by John
CHEMICAL
CALCULATIONS
PRESENTATION OF THE SOLUTION OFA SYSTEMATIC
TYPE WITH IOOO CHEMICAL PROBLEMSPROBLEMS,
ARRANGED PROGRESSIVELY ACCORDING TO
LESSON ASSIGNMENTS
BERNARD M.A.JAFFE,By
Instructor in SchoolChemistry, Jamaica High
New York City
Tankers-on-Hudson New Tork
y
WORLD BOOK COMPANY
2126 Prairie Avenue, Chicago
1927WORLD BOOK COMPANY
THE HOUSE OF APPLIED KNOWLEDGE
Established W.1905 by Caspar Hodgson
T
YONKERS-ON NEW YORK --HUDSON,
2126 PRAIRIE CHICAGOAVENUE,
textbooks intended to be used inChemistry
high school and classesbeginning college
havebeenfound many teachers to containby
rather too few in the mathematicsproblems
of the subject. Yet in examina-chemistry
tions undergiven state as insupervision,
New and in entrance examina-York, college
tions three of tenperhaps questions out
mathematical calculations. Itrequire was
to thehands ofprimarily strengthen teachers
a in some of theby overcoming deficiency
basal texts in that this book ofchemistry
Chemical Calculations was prepared
NWSS : JCC-2
WorldCopyright 1926 by Book Company
in Great BritainCopyright
All rights reserved
WONTED IN tr.S.A.PREFACE
IN an of the results secured in the of
investigation teaching
in 1922school conducted Professor Samuelhigh chemistry, by
R. Powers 'of Teachers Columbia one of
College, University,
the weaknesses found was the of theoutstanding inability
to use chemical arithmetic. Professor Powers writespupils
the students in the schoolsconcerning first-year chemistry
that "fewer than 60 centexamined are able toper compute
the molecular of when the of a liter of theweight gases weight
less than 50 cent areis able to calculate a for-gas given, per
mula from the molecular andweight percentage composition,
cent are toand 40 able make the calculations involv-only per
a of Law. About one ofout three ising knowledge IJoyle's
able to calculate from the the ratiopercentage .composition
between the amounts of in the two oxides of sulfur.oxygen
A little more than 10 cent are able to calculate from theper
the ratio between the amounts ofpercentage composition
in thetwo oxides of theseoxygen nitrogen. Certainly percent-
would be smaller if all the schools had usedages cooperating
this test. The test was used by schools."distinctly superior
The reasons for this weakness are not difficult to find. A
of the various textbooks onstudy elementary chemistry
reveals in most of them a reference to the sub-only passing
when a moreject; or, treatment iscomprehensive given,
both teacher and are a dearth ofpupil byhandicapped prop-
to hand inerly graded problems hand with thego regular
lesson few teachersdaily assignment. Very their stu-give
dents a of chemical calculations.systematic presentation
The ^airrr of this book is to fill the which teachers ofgap
in 'schools have felt exists in most ofchemistry secondary the
textbooks used. To vitalize and make it a morechemistryPrefaceVI
teachers to introduceworkable science has stimulated the
chemical and the trend of the last fewofsolving problems,
seems to be toward more mathematical chemistry. Byyears
method becomes an exact science to the stu-this chemistry
since he soon realizes that data are funda-dent, quantitative
mental and that even the minutest of matter in their
particles
reactions mathematical laws.obey
The in this book are ac-problems progressively arranged
to anumber of which the student soon learns tocording types
are also to of diffi-
recognize. They graded according degree
and order of lesson A minimum ofculty assignment. algebra
is Since the is to teach not mathematics
required. purpose
but arithmetical calculations have been reduced tochemistry,
a minimum. Whole numbers are used for the atomic weights
of the elements. The constant ofchanging
as issued the International and theCommittee, recentby
researches on this The studentisotopes, justify practice.
is the labor of a maze of coldspared wading through figures.
The time saved in out that involve a mul-working problems
titude of can fie used in otherfigures doing problems.
In it is often to dealanalytical work, however, necessary
with a number of with a fine oflarge figures degree accuracy.
solutions must be obtained to save the time of theRapid
chemist. For such work the Chemists' Slide Rule (sold by
Keuffel & Esser is recommended. Besides' theCompany)
CD and CI this slide rule has two sets ofscales, scales with
the and formulas of used elements andsymbols commonly
marked at thecompounds theirpoints representing respective
atomic and molecular thusweights, making theunnecessary
ofuse atomic and molecular tables.weight
This book is todesigned primarily of theaccompany any
more recent textbooks on Part II hasgeneral chemistry.'
Preface vii
for usebeen added and in thoseby first-year college students,
schools where courses in andhigh qualitative quantitative
are offered.
analysis
wishes to hisThe author forexpress gratitude," helpful
advice and to Mr. S. of the
suggestions, Jaffe Boys' High
New York Mr. M. Mendel of the ThomasSchool, Brooklyn, ;
New and Mr. M.Jefferson High School, Brooklyn, York;
his at the School.Dunay, colleague Jamaica High
BERNARD JAFFESUGGESTIONS FOR THE USE OF THIS BOOK
cultivate a method of1. Aim. This book aims to attack
in With aon mathematical chemistry. knowledgeproblems
of the ten of in Part the studenttypes presented I,
will mid little trouble in all the common
solving practically
chemical problems.
2. It is the of the author that all of Part I
Scope. -opinion
should be mastered school student. Part IIby every high is,
on the intended for more mature
whole, students, especially
students.first-year college
3. Time to The introduction of lawsbegin. quantitative
should be reached as as This book shouldearly possible.
be used in with thethen textbook. Theconjunction regular
is to the of thegeneral begin studyprocedure first-type prob-
lem about the fourth, week after the of the coursebeginning
and after chemical law ofelements, compounds, changes,
definite oflawproportions, oxygen, hydrogen, multiple pro-
and the Atomic have been studied.portions, Hypothesis
and the of balanced should beValency writing equations
introduced early.
4. Rate No rules can be set down. Itof progress. rigid
the of in the school cur-depends upon position chemistry
the andmentalriculum, attainments of the the sizeage pupils,
of and other factors. The work should notclasses, varying
be in too doses. In schools on the Daltongiven large operated
or the Winnetka Plan this book is as it
especially valuable,
meets the needs of the individual student.
5. Lesson The book follows theassignments. order of
which have become moretopics or less standard in the teach-
of The student should master eaching chemistry. type prob-
lem before on to the next one. Problems should bepassingfor the Use of This Book ixSuggestions
from Part III to vitalize the lesson. The
assigned daily prob-
lems under each in Part III cover varioustopic type problems.
have been selected to teach chemical facts. ProblemsThey
from the Examinations and the. EntranceRegents College
Board Examinations should be from time to timeassigned
to the student confidence in his to solvegive suchability
problems.
6. Problem book. All shouldproblems be done ,theby
student in a book. Problems shouldspecial problem be
discussed in class the and correctionsfollowing day necessary
made. This clear Thedevelops thinking. proper handling
of these can serve asproblems a review.
7. Review work. The topical of Part IIIarrangement
facilitates reviews. The important equations theclarify
student's ofknowledge and commerciallaboratory prepa-
rations and fix in his mind the chemical and usesproperties
of the substances studied. Part III should ofprove great
value in the final review.
8. Answer book. A the answers to allpamphlet containing
the be obtained teachers from theproblemsmay by publishers.