Processing kodak motion picture films, module 3 analytical procedures

Approximate Calculation of Total Alkalinity
The approximate total alkalinity of a fresh mix can be
calculated from the mix formula and the alkalinity factor * of
each constituent. Table 1, Alkalinity of Processing
Chemicals, lists the various constituents and their alkalinity
factors.
The numerical value of the total alkalinity of 1 litre of a
processing solution is calculated by summing the amounts of
* The alkalinity factor equals the experimentally determined amount of
acid required to adjust 1 g of a chemical to pH 4.3.
Table 1 Alkalinity of Processing Chemicals
Constituent Formula Mole Wt. Eq. Wt.
acid that will bring each of the constituents, considering the
concentrations used in the solution, to approximately pH 4.3.
The sum for 1 litre of solution is then corrected for the
sample size normally used in the analysis by using the
following equation
T. Alk. for the specified sample size =
[mL, proposed sample size][mL, std 0.1 N H 2 SO 4 for 1 litre]
Alkalinity Factor
by Experiment
Acetic Acid CH 3 COOH 60 60 –170.4 *
Ammonium Thiosulfate,
58% Solution
(NH4 ) 2S2O3 148 — 2.4
Anti-Calcium, No. 4,
KODAK
— — — 3.4
Anti-Fog, No. 9,
EASTMAN
— — — 0
Benzyl Alcohol C6H5CH2OH 108 — 0
Borax, 5-hydrate Na 2 B 4 O 7 H 2 O 291 146 70.0
Citrazinic Acid C 6 H 5 NO 4 — — –150.0 †
Color Developing Agent,
CD-2, KODAK
Color Developing Agent,
CD-3, KODAK
— — — 0.7
— — — –44.0 †
Ethylenediamine
(98% by wt)
NH2CH2CH2NH2 — — 290.0
Quadrofos — — — 24
Sodium Bicarbonate NaHCO 3 84 42 120
Sodium Bromide NaBr 103 — 0
Sodium Carbonate,
Anhydrous
Na 2 CO 3 106 53 189 ‡
Sodium Carbonate,
1-hydrate
Na2CO3 H2O 124 62 163
Sodium Hydroxide NaOH 40 40 250 ‡
Sodium Phosphate,
Dibasic, 2-hydrate
Na2HPO4 2H2O 178 — 76.2
Sodium Phosphate,
Tribasic, 12-hydrate
Na2PO4 12H2O 380 127 60.4
Sodium Sulfate Na2SO4 140 — 0
Sodium Sulfite Na 2 SO 3 126 126 76
Sodium Thiocyanate Na 2CNS 81 81 5.3
Sodium Thiosulfate,
5-hydrate,
Na2S2O3 5H2O 248 — 0
Sulfuric Acid (Conc.) H2SO4 98 49 –360
* The mL of standardized 0.1 N sulfuric acid required to adjust 1.00 g (or 1.00 mL) of chemical to pH 4.3.
† These chemicals make a negative contribution to the T. Alk.; i.e., they have a pH less than 4.3.
‡ 1000/(eq wt)(N Acid) = Calculated alkalinity contribution
2 Processing KODAK Motion Picture Films, Module 3, Analytical Procedures H24.03
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