ENGINEERING RESEARCH INSTITUTE UNIVERSITY OF MICHIGAN ANN ARBOR Final Report DETERMINATION OF THE LOW-TEMPERATURE HEAT CAPACITY OF VITREOUS SILICON DIOXIDE, OR QUARTZ, AND OF CRISTOBALITE Edgar F. Westrum, Jr. Associate Professor of Chemistry Project 2148 OWENS ILLINOIS GLASS COMPANY TOLEDO, OHIO June, 1954

ACKNOWLEDGEMENT I would like to express my appreciation to the several graduate students who assisted in these measurements, to Mrs. Enilia Martin who ably handled the calculations involved, and to Dr. Alvin F. Beale, Jr., who collaborated in making the quartz measurements. This work was favored by stimulating discussions with Professor K. Fajans and by the splendid scientific cooperation of the Owens Illinois Glass Company staffs Mr. S. W, Barber's sincere, generous, and thorough collaboration made possible the procurements of exceptionally well characterized samples, an important aspect of the measurements. ii

iF- ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN DETERMINATION OF THE LOW-TEMPERATURE HEAT CAPACITY OF VITREOUS SILICON DIOXIDE, OR QUARTZ, AND OF CRISTOBALITE The purpose of this report is to present a briefs formal summary of the measurements on the low-temperature heat capacity of two samples of Vitreous silica and samples of alpha quartz and cristobalite. The full scientific, summary will be in the form of journal papers, and since this end cannot be achieved without the critical endeavors of Professor K. Fajans (at present in Europe), Mr. S. WA Barber, and other scientists, the present report is made terse and factual to minimize cost and time —and hence delay in the actual paper. It is intended essentially as an interim document for the convenience of the Owens Illinois Glass Company and for the files of the Institute* Such matters as the preparation, identification, and analysis of the samples are not detailed here since this portion of the work was performed or expedited by the Company and are already, therefore, more directly available to them, APPARATU The heat-capacity determinations were made with our adiabatic calorimetric cryostatl (Laboratory Designation, Mark I) shown in Fig. 1. Liquid or solid nitrogen and liquid helium were used as the low-temperature refrigerants The sample was contained in the gold plated, copper calorimeter2 (Laboratory Designation W-5) shown in Fig, 2* Determinations of the heat capacity were made by observing the temperature change produced by the introduction of a measured quantity of electrical energy, Temperatures were measured with a capsule-type platinum resistance thermometer (Laboratory Designation A-1) contained in a reentrant well in the calorimeter. A 160-ohm constantan heater was wound on a cylindrical copper tube surrounding the resistance thermometer, The thermometer was calibrated against the temperature scale of the National Bureau of Standards 1

L -- ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN - from 14 to 3735~K Below 14~K the scale was obtained by fitting the equation R B A + BT2 + CT5 to the resistance at the boiling point of helium and to the resistance and dR/dT and 14~K. It is believed that the temperature scale agrees with the thermodynamic sqale within 0,1~ from 4 to 14~K, within 0,03~ from 14 to 90~K, and within 0,05~ from 90 to 373~K, The thermometer resistance and the power input were measured with an autocalibrated White double-potentiometer, calibrated resistances, and calibrated standard cells, An electric timer operated by a calibrated tuning fork and an amplifier was automatically started at the beginning of the heating period and stopped at the end, EXPERIEENTAL CONDITIONS The masses ( in vacuo) of the various samples run in the calorimeter are indicated below in grams: Quartz 116,1130 Cristobalite 90.5914 1070~ vitreous silica 10563656 3100~ vitreous silica 102.9248 The quartz was in the form of crystalline fragments (about 5 mesh) the cristobalite fine crystals (100 to 150 mesh), and the vitreous, silica i.n in the form of rods about 5 mni in diameter and approximattely the length of the calorimeter,* A pressure of 5-to 4 dm of pure helium gas at 25~C was used to provide thermal:conduction within the calorimeter. The heat capacity of the calorimeter without sample has now been determined on thie separate occasions and hence may be considered well established, As a final test of the accuracy, precision, and reliability of the instrument, the heat capacity of a sample of benzoic acid provided by the National Bureau of Standards was measured. Our determinations are in excellent accord with theirs.

- ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN - EXPER.IITAL RESULTS The measured values of the molal heat capacities are given in Tables I through IV, These data are expressed in terms of the defined thermochemical calorie,- which is equal to 4.1840 absolute joules4. A small correction for curvature (to convert finite increments, AH/AT,)to the derivative, (aH/aT) Cpp, has been applied. Since the data were obtained under only a few cm of helium pressure, they approximate Cp values very closely. The heat capacity versus temperature curve for quartz is presented in Fig, 3, Within the sensitivity of the drawing, the curves for the three other samples would appear identical, The molal heat capacities of these substances are listed at rounded temperatures in Table V. These heat^capacity values: were read from a smoothed curve through the experimental points and are estimated to have a probable error of 0,1 percent above 250K, 1 percent at 100~K and 5 percent at 5~K, The heat capacity was extrapolated to 0~K with a Debye function and values of thermodynamic functions were computed over the entire temperature range for these substances, but only the 250C values are presented in Table VI. Calculations of the apparent characteristic gram atomic Debye temperature are shown in Table VII, DISCUSSION These new data provide definitive values of the heat capacity of these substances above 10~K, An impression of the high precision of the data on quartz relative to literature values may be obtained by reference to Fig, 4. This deviation plot indicates that our data show deviations of the order of 0.01 percent over most of the range, and that the data of Anderson. scatter considerably about our values. The older data of Nernst4 show deviations of approximately 20 percent near 25~K. Koref's data also show considerable deviation. Most of Gunther's5 determinations are beyond the range of the plot. A somewhat similar deviation plot on cristobalite (Fig. 5) presents the deviation of the experimental determinations on cristobalite versus our smoothed quartz Cp curve. This plot indicates again the supe:rior precision of our data compared with previous values. The high-temperature end of the Anderson3 data, however, deviates markedly from the essentially "parallel" behavi-our we find with the quartz data, 5

- ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN - The data for the samples of vitreous silica are presented relative to quartz in Fig. 6. To emphasize the similarity of these data to those of cristabalite at low temperatures, the heat-capacity deviation curve of that substance is also included, The present samples of vitreous silica are so much better characterized than those described in the literature that the present values may be considered definitive, Further discussion of these matters is reserved for the papers to be presented by the various authors involved. Although we have probably carried the measurements to an adequately low temperature for thermodynamical and structural purposes, it will be interesting to determine the heat capacities to even lower temperatures, say 0.90K,. as will be possible in our Mark II cryostat now under construction, A further matter of interest is the absolute entropy, enthalpy, and free energy of the vitreous silica samples at 0~K, These could be deduced from our data when heat-of-solution values for quartz and the several vitreous silicas are available. The measurements would require the expediture of only several grams of the materials, Our request of the Bureau of Standards to consider such measurements has not yet been answered. We have recently found it necessary in the course of other work to plan the construction of a calorimeter capable of handling hot aqueous HF and anhydrous HF and will consider making the above measurements ourselves, It is evident, of course:, that similar measurements would prove desirable in work on the akali oxidesilicon dioxide glass systems and indispensable in the determination of stored energy in irradiated silicon dioxide, These measurements have demonstrated the capabilities of thermal measurements in the study of the structure of vitreous materials. It is unfortunate, thatitwas rtpossible to include tridymite in the series. The discovery of new high-density silica phases produced under high pressure raises other interesting questions. Another related problem of considerable calorimetric interest is the dependence of the free energy of a vitreous phase on composition and annealing history, Presumeably, in this case also thermal measurements would reveal structural details, 4

REFERENCES 1, Westrumi E, F,, Jr,, Hatcher, J. B., and Osborne, D. W., Chemical Physics, 21, 419 (1953). 2, Hoge, H. J,, and Brickwedde, F, G,, J, Res, Nat'l Bur. Standards, 22, 351 (1939). 3. Anderson, C. T., J. Am. Chem. Soc., 58, 568 (1936), 4. Nernst, W., Ann. Physik, 36, (1911). 5. Gunther, P., ( cf. R, Wietzel, Ztschr. Anorg. Chem. 116, 71 (1921) ), 6. Simon, F., Ann. Physik, 68, 241 (1922). 7. Simon, F., and Lange, F., Ztschr. Physik, 38, 227 (1926). 8, Kelley, K. K,, U. S. Bureau of Mines Bulletin 477, Washington, (1950). 5

Figure 1. Cross-sectional schematic diagram of the Mark I cryostat 14 Helium-exit connector 2 Helium-transfer tube 3. Nitrogen-inlet and outlet connector 4,. Sleeve-fitting to helium-transport Dewar* 54 Nitrogen filling tube 6. Helium-transfer-tube extender and cap 7 Screw fitting at inlet of helium-transfer tube 8, Brass vacuum can 9a Outer floating radiation shield 10. Nitrogen tank 11 Helium-exit tube 12^ Economizer (effluent helium-vapor heat exchanger) 13_ Nitrogen radiation shield 14. Helium tank 15. Bundle of lead wires 16 ^ Adiabatic shield 17. Helium radiation shield 18. Ring for block and tackle 19. Windlass 20. Vacuum seal and terminal plate for leads 21, Head plat.e 22. O-Ring gasket 23, Coil spring 24. Supporting string 25. Floating ring 26A Calorimeter 6

Note: For Figure 1 refer to file copy.

Figure 2% Calorimeter (Laboratory Designation W-5) l.. Thermal-conductivity cone 2, Monel helium seal-off tube 35, "Lubriseal" stopcock grease 4# Copper vane 5 Leeds and Northrup platinum resistance thermometer 6, Fiberglass insulated Noa 40 Advance constantan wire 7^ Formvar varnish 8* Gold-plated copper heater well 9. Gold-plated copper heater sleeve 10. Differential thermocouple sleeve 11 Spool to bring leads into thermal equilibrium with calorimeter

VS-6-S W3r "rS-0 OL6-W INSERT -10 -5 CM -I1 5 -4 -3 -2 I W-5 CALORIMETER Figure 2

Figure 3. The Molal heat capacity of quartz the experimental determinations are shown by the centers of the circles 10

QUARTZ 10 I Li I 7 -UI a_ 0 U 300 T~K Figure 5

Figure 4, Deviation of quartz Cp data from oux smoothed curve, The deviations. ACpT = (Cp individual point - Cp smooth curve)T are. represented by open circles. The corresponding deviation of the data of another investigation from our smoothed curve is similarly represented, i<eo, ACpm = (Cp - CP s ented, i-e) ACPT (Cp other investigator C our smooth curve) The solid circles represent the data of Anderson3, the solid triangles those of Nernst4, and the solid square those of Koref,.4 Erratum: Decimal point is in error on the ACp scale For -0.01 read 0 1, etc, 12

*1 agogT OOE OOZ 001 0 I I O~ OZ s 0z -oo 0 -._ _ _ I -I Cr) 0 I I I I I I. I I I I I I I I II It - - zlUvnI

Figure 5a Deviation of cristobalite Cp data from our smoothed quartz curve, The deviation, ACPT., here represents (Cp cristobalite —Cp quartz)T. The open circles represent our experimental points, the solid circles the data of Simon6, and the solid triangles the data of Anderson3. 14

CRISTOBALITE.3 I 0 _J.< et a-3.2.1 0 -. 0 5 20 50 T,~K 100 200 300 Figure 5

Figure 6. Deviation of Cp data on vitreous-silica samples from our smoothed quartz Cp curve, The deviation, ACPT, here represents (Cp vitreous silica —Cp quartz)T. The open circles represent our experimental points on 1070~ vitreous silica, the open squares represent our experimental points on 13000 vitreous silica, The solid triangles present the four determinations of Simon and Lange7, the solid diamonds the data of Nernst4, and the solid circles the data of Simon6 The dashed line represents, for comparison, the smoothcurve heat-capacity deviation of cristobalite relative to that of quartz.

VITREOUS SILICA.3.J 0 T. < U.2.1I 0 0 5 20 50 100 200 300 T.~K Figure 6

TABLE I THE MOLAL HEAT CAPACITY OF QUARTZ (in calories per degree) AT, K Cs AT ~K Cs SERIES I 61.532 65 60 71o42 77.63 84.44 92 02 99.80 107.57 3 064 5.466 6.188 6.218 7.402 7.755 7.802 7.727 1.924 2 127 20393 20690 30025 52.53 57042 62 85 69.50 76.72 35383 5.756 4.095 90,70 98.70 106.84 114097 123.45 SERIES II 4079 5.42 5.90 6.50 7.63 8.88 9.90 10o70 11.68 12.58 13551 14.46 15.61 17.07 18,74 20 62 22.73 25,01 27a43 50o00 32.83 36,00 39 48 43.29 47.64 0.927 0.738 10553 1.398 1.726 1,408 0o960 1,096 1.008 0.985 0.948 0.979 1,352 1.628 1.753 2.019 2,208 2 347 2.480 2 675 2.987 35339 3.626 35984 4.707 o~ool6 0.0016 0,0017 0.0020 0,0020 0. 0027 0.0042 132.14 141,o8 150, 18 159357 168.54 5.069 4,725 6.123 7.169 7.251 70962 8,013 7.881 8,381 8.582 8.800 9 -073 9,120 9.265 9.070 9.094 9.071 9 269 9.298 9,679 9,781 9.581 9,418 9.588 9.916 10.025 1o o61 9,9970 9,801 1.508 1.735 1.993 2.301 2.646 3.321 3.684 4.063 4.433 4.814 5,199 5.581 5.961 6.324 6.678 7.016 755336 7.660 7.974 8.285 8.591 8.884 9 170 9.441 9.718 9.997 10.273 10.519 10,771 0.0066 0,0099 0.0136 0 0201 0,0278 177.62 186 71 195.88 205.16 214 65 0.0371 0.0490 0 0652 C00931 0.1297 224.38 234.07 243.56 253,06 262.81 0,1788 0,2429 0.3184 o 4063 0.5071 272,78 282,82 292 84 302.77 0.6245 0 7612 0o9141 1.o84 1.284 18

TABLE II THE MOLAL HEAT CAPACITY OF CRISTOBALITE (in calories per degree) ATK C T,~K 2 a T, OK T ~K AT, K Cs SERIES I 72.65 78.4o 85 13 92,72 100.51 107.71 115.14 123.08 131533 140.35 149.62 158.83 168.27 177.82 187.09 195.92 204,57 213.21 222.15 231.31 240.64 250.04 5.117 6.391 7.061 8.121 7.456 6.950 7.890 7.990 8,514 9 527 8.998 9.425 9.454 9.646 8.888 8.771 8,515 8.i765 9.109 9.211 9.438 9,378 2 550 2.819 3.143 3.492 35844 4.177 4.514 4.881 5,245 5.630 6.015 6.388 6.754 7 109 7.458 7.748 8.o38 8.326 8.608 8.892 9.176 9.439 265539 274.17 283.86.291.71 300.95 8.874 8.710 8.661 9.067 9.414 9.876 10.117 10. 50 10.584 10.806 7.75 7T83 7.85 8,60 9.32 10.09 11.06 12.23 15.37 14.48 15.76 17.36 19.18 21.14 23.37 25,87 28.61 31.66 34.96 SERIES III 0.555 0,0146 0.627 0.0156 0.671 0,0226 0.619 0.0379 0.831 0.0537 1.074 0.0736 1.227 0.1004 1.064 0.1339 1.139 0.1682 1,418 0.2112 1.791 0.2676 1.848 053342 2.059 0.4087 2.402 0.4962 2.599 0.5935 2.875 0.7002 3.230 0.8220 5 365 0.9545 3.759 1.100 3.831 1.249 4.216 1.414 4.579 1.597 5.373 1.806 6.563 2.060 9.308 2.404 6.570 2.343 6.278 2.632 6.758 2.915 (continued) SERIES II 130,40 139.28 148.06 156.64 165 43 174.61 185.97 193542 202,77 211.93 221.03 235004 238,94 247.74 256.55 8,746 9.005 8,562 8,596 8.985 9.363 9.366 9.527 9.153 9.172 9.026 8,990 8,807 8.808 8.813 5.207 5.585 5 950 6.300 6.646 6.996 7,330 7,661 7.983 8.286 8.572 8.849 9.110 9.577 9.624 38.55 42.34 46.36 50,76 55.74 61.61 69 45 68.06 74.49 80.62 19

TABLE II (continued) THE MOLAL HEAT CAPACITY OF CRISTOBALITE (in calories per degree) SERIES III T "K AT., ~K Cs 87.56 7.126 3.251 95.25 8.238 3.597 103.58 8.422 30981 112.35 9.130 4.386 121.65 9.470 4.812 250.43 8.644 9.440 259.14 8,776 9.693 267.98 8.900 9.937 276,86 8.871 10.178 285,75 8,925 10.424 294,59 8*753 10.656 302.19 6.474 10.832 20

TABLE III THE MOLAL HEAT CAPACITY OF 1070~ VITREOUS SILICA (in calories per degree).-. -K AT, K Cs SERIES II SERIES I 55-76 61.84 67.90 74,43 82,22 90.85 99.70 108,63 117.45 126.18 134.86 143.45 152,15 161.32 170.57 179.46 188.18 197.22 206.44 215538 224.55 253395 242.84 251.96 261.12 270.55 279.56 288,59 297,11 30.429 6.06 6,11 6.oo00 7,05 8.52 8.73 8.97 8,88 8.76 8.70 8.65 8.52 8.89 9.45 9.06 8.72 8671 936 9.07 8.82 9.08 9 36 9.22 9.01 9,32 9.13 9.29 8,79 8.26 6.10 1.842 2,113 2.385 2.677 35.41 5.22 5.87 6.23 7.04 8.03 3.449 3.845 4,249 4.647 5.034 9.03 9.92 10.82 11.79 12.80 5.403 5.758 6.107 6.464 6,812 13.93 15.38 17.20 19.05 20,95 0.85 0.97 0.94 1.07 1.10 0.98 0.85 0.98 0.99 1.06 1.21 1.72 1.93 1.77 2.03 2.08 2.77 2.89 3.27 3556 3.84 4.01 4.36 5.64 5.59 0.0050 0.0093 0,0118 0.0183 0.0294 0.046 0.064 0..082 0.103 0.128 0.159 0.204 0.263 0.327 0,396 0.475 0.569 0.675 0.801 0.944 1.100 1.264 1.441 1.656 1.900 7,128 7.429 7.734 8,037 8.314 23.00 25*43 28.09 31.17 34.59 8.584 8.861 9.127 9,374 9.625 38.29 42.22 46.40 51.40 57,02 9.868 10.105 10.338 10.541 10.711 21

TABLE IV THE MOLAL HEAT CAPACITY OF 130Cr VITREOUS SILICA (in calories per degree) T,~K ril 0 -L. Y J. A Cs AT,0K C SERIES I 5.88 7.01 8.15 9.18 10.12 11.12 12.23 13,30 14.40 15.72 17.45 19.41 21.46 23.69 26,15 28.99 32 08 35,18 38.94 43.20 48.47 54.31 59,19 64.15 69.80 75d55 82.19 89,24 97,25 105.62 113.85 121.99 150,13 138.28 146.69 155.55 164,65 171.22 18o.06 189.16 1.172 1,349 1.099 1.056 0.940 14130 1.163 1.023 1.227 1.467 1.996 2.034 2.082 2.374 2.506 3.222 2,952 3.230 45300 4,215 6,322 5.548 4,401 5.511 5.788 6.941 6,326 7.786 8.220 8.530 7,914 8,374 7,905 8.593 8.422 9.298 8,897 8.603 9.076 9.127 0 0091 o.o163 0.0295 0.0459 00o657 198.16 207.05 215.96 224,99 254o21 8,856 8,928 8.891 9.178 9 265 9.388 93523 9.436 9.364 9.529 7.748 8.o04 8.517 8,593 8.866 9,140 9.392 9.643 9.881 10.137 0,0841 0,1082 0.1348 0.1659 0.2048 243554 252.89 262.26 271.66 281,00 0,2609 0,3198 0.4030 0.4879 0.5822 0,6962 0.8206 0,9529 1,112 1.291 1.519 1.769 290356 299.91 9.597 103.72 9.742 10- 605 SERIES II 55.91 62.01 68o.17 74.47 81.65 89 14 96.58 104,96 113.54 121,90 2,455 2.715 3,025 5.365 3,722 4.100 135032 138,65 146.73 155.42 164.92 6,070 6.141 60176 6.426 7.936 70031 7.849 8.914 8.249 8,.456 8 387 8,271 7.884 9.505 9.487 9.629 9.472 9. 342 9.047 8.987 8.951 9.930 9.004 8.954 9o046 1.855 2.106 2,381 2.664 3.001 3o 360 3.690 4.069 4.460 4.830 5.197 5.545 5.875 6,221 6.586 6.941 7,276 7.594 7.900 8.188 8.459 8.727 8.988 90239 9.486 4.471 4.835 5.189 5.530 5,874 174,48 184.03 193544 202.63 211.65 6.225 6.577 6.819 7.133 7.448 220,62 229 56 238.53 247.49 256.,47 22

TABLE IV (continued ) THE MOLAI T 0 K > HEAT CAPACITY OF 1300~ VITREOUS SILICA (in calories per degree) Ca 9*7733 9.976 10,211 10.442 10.659 265.56 274.68 283.86 293506 302 16 94124 9.137 9.218 9.192 9. 24 23

TABLE V SMOOTHED HEAT CAPACITIES FOR SILICON DIOXIDE (in calories per degree per mole) Quartz 10 15 20 25 35 55 40 45 50 60 70 80 90 100 110 120 150 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 0.0105 0.0567 0.1619 0.3176 0,507 0.718 0.938 1,162 1. 92 1.857 2.328 2.802 3.287 35744 4.209 4.660 5.105 5.534 5.946 6.347 6 o733 6,755 7.101 7.454 7.805 8,133 8.455 8.763 9.061 9.355 9.657 9.918 10,189 10.450 10,703 Cristobalite 0,044 0,185 0. 65 0.559 0.755 0.956 1.156 1.357 1*565 1.991 2.429 2.887 3.363 5.822 4.285 4. 738 5.187 5.617 6.029 6.433 6.821 7.189 7.545 7.887 8.218 8.540 8.851 9.0150 9.442 9.726 10.005 10.277 10.537 10,791 10,088 Vitreous 10700 0.066 0,192 0.562 0.552 0.753 0.958 1.166 15382 1.595 2.0530 2.476 2,936 3,405 3.859 4.311 4.761 5.196 5,614 6.020 6.412 6.790 7.145 7.490 7.826 8.147 8.456 8.756 9.042 9.521 9.595 9.860 10.117 10.5362 lO. 602 9,941 Silica 0,062 0.184 055339 0.535 0.737 0.944 1.156 15368 1.585 2.024 2.461 2,924 3.395 3.842 4.299 4.746 5.182 5.601 6.006 6.598 6.774 7.136 7.477 7.812 8.136 8.441 8.741 9,050 9.510 9.585 9.852 10 *111 10.566 10, 609 275.16 10.006 298.16 10.658 9.935 10o. 744 10, 564 10.565

TABLE VI MOLAL THERMODYNAMIC FUNCTIONS FOR SILICA AT 298,16~K (in calories per degree) Literatures This Research O O S*-S (H~-H)/T (F~-H8)/T s ~s (+ 0o,01) (t 0.006) (t 0.005) Quartz lO.00 t 0.10 9,880 5.543 45337 Cristobalite 10.20 t 0.10 10.377 5 643 474 10700 vitreous 10,53 0,2 10,374 5.609 4,765 silica 25

TABLE VII APPARENT DEBYE 8 CALCULATIONS (Characteristic temperatures per gram atom of silica) -itreous Silica o100 1070~ T,.K Quartz " '-'jilI' 10 15 20 25 50 510.1 436.1 410 5 409.5 420o.0 35 40 45 50 60 43559 459.3 475 o1 495,2 534 7 70 80 90 100 110 573.0 609.0 640 0 671 h5 699.4 120 130 140 150 160 726,4 751.1 774.4 796.5 818.1 Cristobalite 507.4 294o0 312.6 338.7 367.3 395.4 423.1 449.9 475.0 521,8 563.9 601.1 634,o 665,7 694.9 720.8 745.6 7690 791.4 812.6 852.3 850 7 868,9 886.4 90350 918,3 952 9 946.3 959*0 971.4 982,5 991.8 999.6 1oo6,2 282.2 294.6 520,4 343.8 370,3 276.4 290 *4 313.6 340,2 367o6 560..9 598.0 630,8 650.8 664.1 695,1 559.6 597.0 630,7 662.8 692,8 39701 423,1 448.6 472.9 518.5 395.1 421,8 447.0 4711,8 517.9 720,4 745,8 770 1. 7935.2 814.9 719.2 744.7 769,2 792.1 813.8 170 180 190 200 210 220 250 240 250 260 270 280 290 500 838,1 857.4 875.9 892.8 909.0 924,7 940,3 954. 3 967.0 978,9 989...4 999,2 1008.5 1017.0 835.7 855*5 875.0 893.0 907.4 834.4 854,7 873.9 891.7 909.0 926.9 942.3 957.1 971,0 985.8 925*5 940,9 955,7 969.4 982,2 995,8 1006*9 1017.0 1026.7 994,3 1005,7 1016.1 1025. 4 26