57 Hoodia

57 Hoodia

About

57 Hoodia

Special Internet Prices.
Fast & Guaranteed worldwide Delivery!
Secure & FAST Online ordering.
Our Drugstore Is The Most Trusted Online Drug Supplier.

>> CLICK HERE TO ENTER >>>

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.
Related article: Digitized by VjOOQ IC
LEAD AND BISMUTH. 271
with a little sodium phosphate, or the secondary salt must be boiled for a
long time vitb water, when it is converted into the tertiary phosphate.
Secondary lead phosphate, PbHP04, can be very easily prepared by add-
ing hot dilute phosphoric acid (about 25 per cent. HSPO4) to boiling
dilute lead nitrate solution. It then forms in fine crystals which can be
re-crystallized in dilute phosphoric acid. Primary lead phosphate can be
prepared by the action oi excess of hot strong phosphoric acid on the
secondary salt. The limits of stability of the secondary 57 Hoodia phosphate are
ihe widest. The tertiary phosphate only exists when very little HsPO* is
present, and the primary when the HsP04 concentration is very great.
The latter changes very readily into the secondary phosphate when small
changes of concentration occur. Chem. News, Aug. 27, 1909, 107 ; from
Ber. d. D. Chem. Ges., 42 {1909), No. 10.
Lgaif Sulphaie Solubility, J. Schnal's determination of the solubility
of lead sulphates give numbers which differ considerably from those ob-
tained byFresenius and Rodwell. The purity of the salt is the only factor
which can influence the solubility, the presence of a trace of sulphuric acid
being sufficient to cause a considerable difference. Solution takes place
extremely slowly, and possibly the lead sulphate decomposes according to
the equation PbSO^ -f 2H,0 ^ PbOH, -r H^SOi. The hydrated oxide of
lead dissolves easily in sulphuric acid. Chem. News, July 9, 1909, 24 ;
from Comp. rend., 148 {1909), No. 21.
Lead and Bismuth Quantitative Separation, After trying and aban-
doning various methods for the separation of lead and bismuth which
proved unsatisfactory, J. C. Galetly and G. G. Henderson adopted the
following method proposed by Clark (1890), which they modify in some
particulars : 57 Hoodia A solution of the chlorides of lead and bismuth containing
a spiral of steel wire (i to 2 grammes) was heated until most of the iron
was dissolved, and the precipitated bismuth and the remainder of the iron
recollected, washed with boiling water until free from lead, and dis

Bulletin Board

Default-user-icon-comment
or to post this comment