Part 27 (1/2)

___________________________________________________________________________ | | | | BURETTE | DIFFERENCE | OBSERVED | DIFFERENCE | CALCULATED READINGS | | WEIGHTS | | CORRECTION _______________|______________|______________|______________|______________ 0.02 | | 16.27 | | 10.12 | 10.10 | 26.35 | 10.08 | -.02 20.09 | 9.97 | 36.26 | 9.91 | -.06 30.16 | 10.07 | 46.34 | 10.08 | +.01 40.19 | 10.03 | 56.31 | 9.97 | -.06 50.00 | 9.81 | 66.17 | 9.86 | +.05 _______________|______________|______________|______________|______________

These data to be obtained in duplicate for each burette.

!Page B!

Date

DETERMINATION OF COMPARATIVE STRENGTH HCl vs. NaOH

___________________________________________________________________________ | | DETERMINATION | I | II _________________________|________________________|________________________ | | | Corrected | Corrected Final Reading HCl | 48.17 48.08 | 43.20 43.14 Initial Reading HCl | 0.12 .12 | .17 .17 | ----- ----- | ----- ----- | 47.96 | 42.97 | | | Corrected | Corrected Final Reading HCl | 46.36 46.29 | 40.51 40.37 Initial Reading HCl | 1.75 1.75 | .50 .50 | ----- ----- | ----- ----- | 44.54 | 39.87 | | log cc. NaOH | 1.6468 | 1.6008 colog cc. HCl | 8.3192 | 8.3668 | ------ | ------ | 9.9680 - 10 | 9.9676 - 10 1 cc. HCl | .9290 cc. NaOH | .9282 cc. NaOH Mean | .9286 | _________________________|________________________|________________________

Signed

!Page C!

Date

STANDARDIZATION OF HYDROCHLORIC ACID ===================================================================== | | Weight sample and tube| 9.1793 | 8.1731 | 8.1731 | 6.9187 | ------ | ------ Weight sample | 1.0062 | 1.2544 | | Final Reading HCl | 39.97 39.83 | 49.90 49.77 Initial Reading HCl | .00 .00 | .04 .04 | ----- ----- | ----- ----- | 39.83 | 49.73 | | Final Reading NaOH | .26.26 | .67 .67 Initial Reading NaOH | .12 .12 | .36 .36 | --- --- | --- --- | .14 | .31 | | | .14 | .31 Corrected cc. HCl | 39.83 - ----- = 39.68 | 49.73 - ----- = 49.40 | .9286 | .9286 | | log sample | 0.0025 | 0.0983 colog cc | 8.4014 - 10 | 8.3063 - 10 colog milli equivalent| 1.2757 | 1.2757 | ------ | ------ | 9.6796 - 10 | 9.6803 - 10 | | Normal value HCl | .4782 | .4789 Mean | .4786 | | | =====================================================================

Signed

!Page D!

Date

DETERMINATION OF CHLORINE IN CHLORIDE, SAMPLE No.

===================================================================== | | Weight sample and tube| 16.1721 | 15.9976 | 15.9976 | 15.7117 | ------- | ------- Weight sample | .1745 | .2859 | | Weight crucible | | + precipitate | 14.4496 | 15.6915 Constant weights | 14.4487 | 15.6915 | 14.4485 | | | Weight crucible | 14.2216 | 15.3196 Constant weight | 14.2216 | 15.3194 | | Weight AgCl | .2269 | .3721 | | log Cl | 1.5496 | 1.5496 log weight AgCl | 9.3558 - 10 | 9.5706 - 10 log 100 | 2.0000 | 2.0000 colog AgCl | 7.8438 - 10 | 7.7438 - 10 colog sample | 0.7583 | 0.5438 | ------- | ------- | 1.5075 | 1.5078 | | Cl in sample No. | 32.18% | 32.20% | | =====================================================================

Signed

STRENGTH OF REAGENTS

The concentrations given in this table are those suggested for use in the procedures described in the foregoing pages. It is obvious, however, that an exact adherence to these quant.i.ties is not essential.

Approx. Approx.

Grams relation relation per to normal to molal liter. solution solution

Ammonium oxalate, (NH_{4})_{2}C_{2}O_{4}.H_{2}O 40 0.5N 0.25 Barium chloride, BaCl_{2}.2H_{2}O 25 0.2N 0.1 Magnesium ammonium chloride (of MgCl_{2}) 71 1.5N 0.75 Mercuric chloride, HgCl_{2} 45 0.33N 0.66 Pota.s.sium hydroxide, KOH (sp. gr. 1.27) 480 Pota.s.sium thiocyanate, KSCN 5 0.05N 0.55 Silver nitrate, AgNO_{3} 21 0.125N 0.125 Sodium hydroxide, NaOH 100 2.5N 2.5 Sodium carbonate. Na_{2}CO_{3} 159 3N 1.5 Sodium phosphate, Na_{2}HPO_{4}.12H_{2}O 90 0.5N or 0.75N 0.25

Stannous chloride, SnCl_{2}, made by saturating hydrochloric acid (sp.

gr. 1.2) with tin, diluting with an equal volume of water, and adding a slight excess of acid from time to time. A strip of metallic tin is kept in the bottle.

A solution of ammonium molybdate is best prepared as follows: Stir 100 grams of molybdic acid (MoO_{3}) into 400 cc. of cold, distilled water. Add 80 cc. of concentrated ammonium hydroxide (sp. gr. 0.90).

Filter, and pour the filtrate slowly, with constant stirring, into a mixture of 400 cc. concentrated nitric acid (sp. gr. 1.42) and 600 cc. of water. Add to the mixture about 0.05 gram of microcosmic salt.