36A
ANALYTICAL
H O W TO CHELATE
CHEMISTRY
CALORIMETER
Parr ACCESSORIES
(pronounced "Key-late")
HAVE MANY LABORATORY
USES
THERMOMETER R E A D I N G LENS A 3-power magnifier in a telescopic mounting. Easily c l a m p e d o n any thermometer or burette of 6 to 16 mm. diameter. PARR N o . 3003
PELLET
...Versene
PRESS
A convenient hand-operated press with stainless steel punch and die for compressing powdered materials into y2" dia. pellets up to y2" thick. Special y4" d i a . p u n c h a n d die a v a i l a b l e a l s o . PARR N o . 2811
VERSENE* CHELATES CATIONS Before you can chelate foreign metallic ions in solutions you must have a powerful chelating agent such as Versene. This is a compound that will inactivate cations with the formation of inner ring structures in the molecule. It makes the metallic ion become part of the rings. This is a valuable thing to k n o w because it will prevent all kinds of contamination caused by cations.
TURBIDIMETER A visual extinction type turbidimeter used mainly for rapid sulfur and sulfate determinations. Sturdily constructed — easy to operate — moderately priced. PARR Spec. 2400 gives c o m p l e t e d e t a i l s .
PREFERENTIAL CHELATION W h e n Versene is added to a mixture of various metallic ions chelation will be preferential. That is, one metal will be complexed before another. When the first is exhausted the second will be inactivated and the process will go on until either metallic ions o r Versene are used u p . Page 7 of Section I of Bersworth's Technical Bulletin N o . 2 gives a table which shows the order of chelation of some of the c o m m o n metals at various p H ' s . Send for it.
Ask your PARR Dealer for prices, or write direct.
VERSENES*—POWERFUL CHELATING AGENTS T h e Versenes, made only by the Bersworth Chemical Company under processes originated, developed and patented by F. C. Bersworth, are the most powerful chelating agents known. They are exceptionally stable at h i g h temperatures and all pH's. Quality standards of manufacture are so high that uniform complexing power is guaranteed for either sample o r carload quantities. Ask for TechnicalBulletin#2.WriteDept. V for samples. Chemical counsel available. V E R S E N E * W A T E R T E S T K I T . Tells Total Hardness In 2 minutes. Accurate t o \ g r a i n p e r g a l . Versenate m e t h o d . Complete with instructions $ 5 . 0 0 P o s t p a i d . * T r a d e M a r k Registered
"CHEMISTRY'S MOST PRECISE CHEMICALS"
BERSWORTH CHEMICAL CO. FRAMINGHAM, MASSACHUSETTS
Parr
Warehouse Stocks G e o r g e M a n n & C o . , Inc. - Providence, R. I. · W a s a t c h Chemical C o . - Salt Lake City G r i f f i n Chemical C o . — San Francisco - Los Angeles · K r a f t Chemical C o . — Chicago Siegel Chemical C o . - Brooklyn, N . Y.
·
C. S. Tanner C o . - Charlotte, N . C.
ttiHG » S
Bar a d a & P a g e , Inc. Dallas - Houston - N e w Orleans - O k l a h o m a City - St. Louis - Tulsa C o p y r i g h t 1 9 5 2 Berswoith
Chemic*l_Company
Wichita
lNSTRUMENT COMPANY
1 -*' HRË: RÉACTION «OUIPM ENT ;
