The Students' Guide in Quantitative Analysis - Free Ebooks Library

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APPENDIX.
PREPARATION O!-' REAGENTS,
..^ n Prepare- Anunonium Citrate Soluiion.^ 37o grams of
(,) T6 Prcpau
^^ ^^ ^^^^^^ . ^^,^,,1^, neutralize wLth
"^'"^^TfrepareMolymc Solution.^T^^s^oX.. 100 grams of molyb-
di "acid in 4^ gr.ms or 4-7 cc. of a..mon,a of sp.c.hc gravUy 0.96
tdplthesoLion thus obtained into ,,sco grams or ,,350 cc of
nitricacid of specific gravity 1.20. Keep tt,e n,Lxturc m awarm p
ace
?o evcral day . or undl a portion heated to 40' C. deposHs no yel ow
predp'ute of ammoniun. phospho-molybdate. Decant the solution
from any sediment, and preserve in glass-sloppered vessels.
il To Prepare Ammonium Nitrate 5'./«^.-««.-Dissol ve 200 grams
of commercial ammonium nitrate in water and bring to a volume ol
''^''\^\?oPrepare Magnesia M.r/^r^.-Dissolve 22 grams of recently
5Jtcd calcined magnesia in dilute hydrochloric acid, avoiding excess
Jf the latter Add a little calcined magnesia in excess, and boil a
few minutes to precipitate iron, alumina, and phosphoric actd, filter,
add •'80 grams of ammonium chloride, 700 cc. of ammonia of specific
gravity 0.96. and water enough to make tiie volume of two liters.
Instead of the solution of 22 grams of calcined magnesia i to grams
of crystallized magnesium chloride (MgCU, 6H,0) may be used.
(5) DiluU Ammonia for Washing.—One volume ammonia of
specific gravity o.g6 mixed with three volumes of water, or usually
one volume of concentrated ammonia with six volumes of water,
(6) Nilrate of Magnesia.— Yy\sso\\'^ 320 grams of calcined mag-
nesia in nitric acid, avoiding an excess of the latter ; then add a little
calcined magnesia in excess, boil ; filter from excess of magnesia,
ferric oxide, etc., and bring to volume of two liters,
METHODS OF BETERMTNING POTASH.
METHOD OF LINDO AS MODIFIED BY CLADDING.
(1) Superphosphates. ~~^o\\ 10 grams of the fertilizer with 300 cc.
of water for ten minutes. Cool tlie solution ; add ammonia in slight