. Journal. aring a densityof 1-4193. (—This and all subsequentdensities are referred to 15°/4° in vacuo.) Up toa temperature of 20° C. the experiments were madein stoppered bottles. From 30° C. upwards thetime of exposure was very much reduced so that 66S SELIGMAX AND WILLLVMS—ACTIOS OF XITRIC ACID OX ALUMINIUM. [June 30. laio. the experiments could t>e niade without dangerof dilution in a fiask containing about 1 litre ofthe acid. The siuiie aoid was used are given in Table I. Table I. Temp. lime of exposure. Rate of dUsolutioD. OC. 41 hours 5-5 »,. 216 13 20 „
. Journal. aring a densityof 1-4193. (—This and all subsequentdensities are referred to 15°/4° in vacuo.) Up toa temperature of 20° C. the experiments were madein stoppered bottles. From 30° C. upwards thetime of exposure was very much reduced so that 66S SELIGMAX AND WILLLVMS—ACTIOS OF XITRIC ACID OX ALUMINIUM. [June 30. laio. the experiments could t>e niade without dangerof dilution in a fiask containing about 1 litre ofthe acid. The siuiie aoid was used are given in Table I. Table I. Temp. lime of exposure. Rate of dUsolutioD. OC. 41 hours 5-5 »,. 216 13 20 „ . 24 4S 30 „ o 110 -iO,, .) 206 50 „ ?> 4S3 60 „ 1 92 70 „ 1 1770 80., 1 3430 i 6300 100., * 10750 110,, i 15800 120,, 1/5 21000 Series r>. Effect of concentration.—The experiments of thisseries were carried out «-ith annealed metnlconUiining 0-21 % Si, 019% le. 000% Cu. Thetemperature was 20^ C. thi»)ugliout. The numeri-cal results are given in Table II. Table II. 22,000. 0 C. 10° 20° 30° 40° 50° C0° 70° 80°FIQ. II. 90° 100° 110° 120° Visible evolution of gas first occurred at 80° rates of dissolution and their logarithmshave been plotted in Fig. II., from which it willbe seen that between 20° C. and 00 C. the latterlie practically in a straiglit line. At the iiighesttemperatures tlie curve changes, possil)ly owingto the very rapid evolution of gas from the surfaceof the metal. A sindLar experiment made withmetal containing 0-21% of silicon and 019% ofiron gave exactly analogous results. Moreover,similar were found to obtain with acidof ] 5 and dilute acid containing 22 „ the latter case, however, there was one anom-alous factor which is still the subject of investig-ation. Composition of acid. %HNO, Approxi-mate %by vol. o(1-42 acid. Remarl<9. 1-6245 99—100 Acid prepared by distil-ling furaiug acid underreduced pressure on toalumtniunt contained ina tube whidi was sub-sequently seale
Size: 1370px × 1824px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectchemist, bookyear1882
