1、 FORD LABORATORY TEST METHOD AH 005-01 Date Action Revisions 2000 08 07 Editorial no technical change A. Cockman 1992 04 27 Printed copies are uncontrolled Page 1 of 2 Copyrig ht 2000, Ford Global Technologies, Inc. ANALYSIS OF PLATING SOLUTIONS TIN PLATING Solutions Required Barium Chloride - 10 %
2、Solution Weigh 100 g of BaCl 2 2H 2 O, dissolve in distilled water, and dilute to 1000 mL. Standard Hydrochloric Acid - 1 N See Procedure AH 1 - 1 for preparation of this ac id. Standard Iodine for Tin Determination - Approx. 0.1 N Preparation 12 - 13 g I 2 20.0 g KI Dissolve potassium iodide in the
3、 least possible amount of distilled water and then add iodine crystals and stir until dissolved. Dilute to 1000 mL in a volumet ric flask. Mix thoroughly and store in a dark glass stoppered bottle. Standardize as follows: Weigh 0.2 - 0.3 g of pure tin to 0.1 mg and dissolve in 50 mL of concentrated
4、HCl in a 500 mL Erlenmeyer flask. Add acid to maintain volume. When solution is complete dilute to 100 mL and add 0.2 g of antimony powder. Place a one hole rubber stopper in the neck of the flask and insert one end of a glass delivery tube through the hole so that it extends just below the bottom o
5、f the stopper. Allow the other end to dip about 2/3 of the way down in a 300 mL tall form beaker. Add 250 mL of water to the beaker and 3 heaping teaspoons of sodium bicarbonate and stir to make a saturated solution. Place the flask on the hot plate and boil for twenty minutes. Add one teaspoon of s
6、odium bicarbonate to the beaker, stir carefully and cool the flask and beaker in running water to 23 +/ - 2 C. When cool, remove stopper and delivery tube, add 5 mL of starch solution and titrate immediately with 0.1 N iodine solution to a de finite blue color. g of pure Sn = factor (g Sn per mL) mL
7、 of iodine Starch Solution Add 1 g of soluble starch to 25 mL of cold distilled water and mix thoroughly. Add 150 mL of boiling water, stir and boil for 10 minutes. Cool, add 3 mL of chloroform to preserve the solution. FORD LABORATORY TEST METHOD AH 005-01 Page 2 of 2 Copyright 2000, Ford Global Te
8、chn ologies, Inc. Thymolphthalein Indicator Dissolve 0.4 g in 50 mL of ethyl alcohol. Add 50 mL of water. Store in a drop bottle. Conditioning and Test Conditions All test values indicated herein are based on material conditioned in a controlle d atmosphere of 23 +/ - 2 C and 50 +/ - 5 % relative hu
9、midity for not less than 24 h prior to testing and tested under the same conditions unless otherwise specified. Procedure Sodium Stannate 1. Pipette 5 mL of plating solution into a 500 mL Erlen meyer flask. 2. Add 100 mL HCl (1:1) and 2 g of antimony powder. 3. Place a one hole rubber stopper in the
10、 neck of the flask and insert one end of a delivery tube through the hole so that it extends just below the bottom of the stopper. Fill a 300 mL be aker 2/3 full of water, add 3 heaping teaspoons of sodium bicarbonate and stir to make a saturated solution. Insert the other end of the delivery tube a
11、bout half way down in the beaker. 4. Place the flask on the edge of the hot plate and boil for twenty minutes. 5. Add another teaspoon of sodium bicarbonate to the beaker, mix carefully and place the flask and beaker in running water and cool to 23 +/ - 2 C. (During cooling, some sodium bicarbonate
12、will be sucked back into the flask and carbon dioxide li berated until pressure is equalized. The blanket of CO 2 thus formed prevents oxidation of the reduced tin prior to titration.) 6. When cool, remove stopper and delivery tube and add 5 mL of starch solution and titrate immediately with standar
13、d 0.1 N iodi ne solution to a blue end point. mL of Iodine x factor x 26.7 = oz. Sn per gal oz. Sn per gal x 2.25 = oz Na 2 SnO 3 3H 2 O per gal Sodium Hydroxide 1. Pipette 10 mL of the plating solution into a 300 mL Erlenmeyer flask. 2. Add 60 mL of BaCl 2 solution (10 %) and enough water to thin t
14、he solution so it may be titrated. 3. Add a few drops of thymolphthalein indicator. 4. Titrate with 1 N HCl to disappearance of the blue color. mL of 1 N HCl x 0.5340 = NaOH in oz/gal Chemicals, materials, parts, and equipm ent referenced in this document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities.
