Processing kodak motion picture films, module 3 analytical procedures

CALCULATIONS
mL AgNO 3 that would be consumed by the thiocyanate, as
measured by Method D94-0003/1:
NaSCN, g/L = (mL AgNO3 )(N AgNO3 )(eq. wt. NaSCN)(1000)
(mL sample)(1000)
where:
N AgNO3 = Normality of AgNO3 in meq./mL
eq. wt. = 81.08 mg/meq
mL sample = 5.0 mL
Solve the equation for mL AgNO 3
g/L NaBr
where:
1000 =
Example:
factor to convert mg to g in the numerator
and mL to L in the denominator
5.97 g/L NaSCN = (mL AgNO3)(0.0491 N AgNO3)(81.08)(1000) (5.0)(1000)
mL AgNO3 =7.50
NaBr, g/L = [(mL AgNO3 titrated) – (mL AgNO3 from thiocyanate)](N AgNO3 )(eq. wt.)(1000)
(mL sample)(1000)
mL AgNO 3 titrated = Total mL AgNO 3 consumed by both Br - and SCN -
mL AgNO3from thiocyanate = Calculated mL of mL AgNO3 from analyzed
amount of sodium thiocyanate
N AgNO3 = Normality of AgNO3 in meq./mL
eq. wt. = 102.91 mg/meq
mL sample = 5.0
1000 =
factor to convert mg to g in the numerator and mL
to L in the denominator
NaBr, g/L = [(14.2 mL AgNO3) – (7.50 mL AgNO3)](0.0491 N AgNO3)(102.91)(1000) (5.0)(1000)
NaBr, g/L = 6.8 g/L
Processing KODAK Motion Picture Films, Module 3, Analytical Procedures H24.03 3