Robert Vácha Kamenice 5, A4 2.13 robert.vacha@mail.muni.cz Vlastnosti vody TABLE 4.1 Common Properties of Water Molecular Formula Ha0 Mass 18.0153 amu (or g/mol) 2.99072 x 10"26 kg/molecule Molecular volume (liquid) 14.6 Á3/molecule (van der Waals) Concentration 55.345 M (mol/L) Number density 3.34 x 102s m-3 Density 997.05 kg/m3 (liquid, 25DC, 1 atm) 999.97 kg/m3 (liquid, 3.984°C, 1 atm) 916.72 kg/m3 (solid, 0°C, 1 atm) Melting point 0°C (273.15 K) Boiling point 100.0°C Specific heat 4182 J/(kg'K) (constant pressure) Dielectric constant 78.5f0 Viscosity (dynamic) 0.8909 x 10"3 Pa s (25°C) 1.0016 x 10 3 Pa s(20°C) Surface tension 0.07198 J/m3 3 74 anomálií vody http://www1 .lsbu.ac.uk/water/water anomalies.html • Phase anomalies P1-P13 • Density anomalies D1-D22 • Material anomalies M1-M18 • Thermodynamic anomalies T1-T11 • Physical anomalies F1-F10 4 Hustota vody • charakteristická vlastnost vody • významná pro existenci života na Zemi • hustotní maximum při 4 °C —► led má menší hustotu než kapalná voda, a proto plave na hladině 1000.25 1000.20 Jf 1000.15 I' 1000.10 c Q S 1000.05 1000.00 999.95 0.0 2.0 4.0 6.0 8.0 Temperature (X) Zvláštnosti vody měrná tepelná kapacita • voda má silnou schopnost absorbovat teplo (teplota takového systému roste jen zvolna) TABLE 4.3 Heat Storage: Q = mCpAT Substance c„(kcal/kg-K) Lead 0.031 Mercury 0.033 Copper 0.092 Glass 0.20 Marble 0.21 Aluminum 0.214 Ice |-10°C) 0.53 Ethanol 0.581 Sea water 0.93 Water 1.00 " Specific heats of substance at constant pressure Zvláštnosti vody tepelná vodivost • voda má velkou tepelnou vodivost, asi 4x větší než jiné kapaliny TABLE 4.4 Heat Transport: Thermal Conductivities of Selected Substances Substance Thermal Conductivity (W Air 0.0256 Nitrogen (300 K/80 K] 0.026/0.13 Carbon tetrachloride 0.10 Di phenyl 0.14 Toluene 0.13 Water 0.60 Styrofoam 0.010 Ice (0°C| 2.2 Copper 390 Diamond 2450 Zvláštnosti vody skupenské teplo • skupenské teplo fázových prechodu je asi 3x větší než u jiných kapalin Table 4.5 Latent Heats of Fusion, Vaporization, and Corresponding Temperatures for Water and Several Oth r Substances Melting Point Latent Heat of Boiling Point Latent Heat of (•C) Fusion, L, (J/kg) <°C) Vaporization, L. (J/kg) Ethanol -114.4 10.8 x 10'- 78.3 8.55 x 105 Methanol -96 9.92 x 10" 64.7 10.7 x 10B Acetone -94.7 9.80 x 10" 56.5 5.51 x 105 Mercury -38.9 1.14 x 10r 356.6 2.96 x 105 Water 0.0 33.5 x 10" 100.0 22.6 x 105 Benzene 5.5 12.6 x 10s 80.1 13.7 x 105 Glycerol 17 20.6 x 10" 290 9.57 x 10s 8 Zvláštnosti vody nízká viskozita TABLE 4.2 Resistance to Movement Viscosities of Fluids (25°C) Fluid Viscosity iPa-s) Air 1.8 x 10"5 Acetone 3.06 x 10J Methanol 5.44 x 10-" Benzene 6.04 x 10 " Water 1.0 x 1(H Ethanol 1.07 x 10-3 Methanol 0.544 x 10-3 Blood 2.3 x 10-3 Sulfuric acid 2.42 x 10-= Motor oil (No. 10) 0.2 Glycerol 1.5 Glucose (solid} 6.6 x 10*1D 2,0 mPa s ♦10 +20 +30 +40 Zvláštnosti vody povrchové napětí • voda má velké povrchové napětí • znemožňuje vytečení malými otvory většina kapalin má při nízkém povrchovém napětí i nízkou viskozitu, ale voda má vysoké povrchové napětí a nízkou viskozitu TABLE 4.6 Surface Tem Pyridine Sulfuric acid Glycerol Hydrazine Water Tissue fluids Soapy water Lung surfactant Water (with but Lino I) and Surface Tensi Surface Tensions (w/air) I, (N/m or J/m2) 0.0221 0.0227 0.0252 0.0288 0.0380 0.0551 0.0640 0.0667 0.0728 (25°C) 0.0588 (100"C) (m/s) 20.6 82.4 47.7 2.28 0.0445 10 Zvláštnosti vody dielektrická konstanta • voda má jednu z nejvyšších dielektrických konstant mezi kapalinami TABLE 4.7 Dielectric Properties of F jidsa Static Dielectric Substance Constant, e Dipole Moment (Debye) Hexane 1.9 0.00 Benzene 2.3 0.00 Diethyl ether 4.3 1.15 Chloroform 4.8 1.15 Ammonia 16.9 1.47 Acetone 20.7 2.72 Ethanol 24.3 1.68 Methanol 32.6 1.66 Dimethyl sulfoxide 48.9 3.96 Water (298 K) 78.5 1.84 (gas) (Liquid, 273 K) 88 2.5-31 n liquid and solid?) (Ice, 273 Ki 91.5 Forma mide 110.0 3.37 a Water has a high dielectric constant and r Im ■ve y w permanent elec- trlcdlpole mome Zvláštnosti vody dielektrická konstanta • voda má jednu z nejvyšších dielektrických konstant mezi kapalinami TABLE 4.7 Dielectric Properties of F jidsa Static Dielectric Substance Constant, e Dipole Moment (Debye) Hexane 1.9 0.00 Benzene 2.3 0.00 Diethyl ether 4.3 1.15 Chloroform 4.8 1.15 Ammonia 16.9 1.47 Acetone 20.7 2.72 Ethanol 24.3 1.68 Methanol 32.6 1.66 Dimethyl sulfoxide 48.9 3.96 Water {298 K) 78.5 1.84 (gas) (Liquid, 273 K) 88 2.5-3 (in liquid and solid?) (Ice, 273 Ki 91.5 Forma mide 110.0 3.37 a Water has a high dielectric constant and r latively low permanent elec- trlcdlpole mome 13 Zvláštnosti vody bod varu pro osatní látky s vodíkovými vazbami H? i c B Pt 40 20 0 -20 -40 -60 -80 -100 ls~- , ,HF \ \ \ ■ 1 \ \ * • m \ \ Hl 1-, - ' for 'i Kapalná voda x led • počet sousedů je v kapalné vodě 5 v ledu 4 • průměrný počet vodíkových vazeb na molekulu je v kapalině -3.5 v ledu 4 • úhel H-O-H je v kapalině 104.5° = menší než v ledu 109.5° • molekuly vody mohou vyplňovat mezery přítomné ve struktuře ledu • v ledu je vyšší protonová vodivost a mobilita (protony přeskakují podél sítě vodíkových vazeb - Grotthussův mechanismus) 17 Autoionizační vlastnost vody WW WW Water Water Hydroxide Hydronium Normální led Ih 20 Kubický led Ic ■m m. <*> m> ^ v ^ *V^< Další ledy Klatráty Modely vody SPC, SPC/E, TIP3P, TIP4P, TIP5P..... http://www1.lsbu.ac.uk/water/water_models.html 25 Vodní mýty Paměť vody 1987: Jacques Benveniste Nature Editor John Maddox NATURE VOL 338 nature It is no disrespect to any of those concerned to compare the dilemma created for Nature by these events to that occasioned a year ago by the article in which Professor Jacques Benveniste and colleagues claimed that indefinitely diluted reagents retain their biological effectiveness. The claim flies in the face of orthodox belief, but the data available are insufficient for a careful judgement of its validity. But on this occasion, Nature has followed Paměť vody Autokorelační funkce vody 1.0 O.B 0.6 \ CS data -Theory ......Transverse -------- Longitudinal - ÍS" 0.4 0.2 \ 0.0 -0.2 •"•— --" ) 50 100 150 200 250 3O0 350 400 450 500 t(fs) 550 Homeopatie + netoxické (ve své době revoluční) - nejde za efekt placeba 28 Polyvoda 1966 - Nikolaj Fedyakin a Boris Deryagin (Technologický Institut Kostroma) Bod varu: 200 C Bod tání: -30 C Specifické infračervené spektrum. 1968: Velká Británie, USA - Desmond Bernal NATURE VOL. 224 OCTOBER 1 I 1969 "Anomalous" Water Sie,—A report on tile properties of ;'anomalous'' water appeared recently in AWre (222, 159; 1960). The probable structure of this phase, wan reported by Lippiii-eott ei al.1 who refer to the phase as polywater, a term descriptive of the structure. After being convinced of the existence of polywater, T am not easily persuaded that it is not dangerous. The consequences of being wrong about this matter are so SCriouS that only positive evidence that there is no danger would bo acceptable, Only the existence of natural (ambient) mechanisms which depolymcmc the material would prove its safety. Until such mechanisms aro known to exist, I regard the polymer as the most dangerous material on earth. Every effort must be made to establish, the absolute safety of the material before it in commercially produced. Once the polymer nuclei become dispersed in the soil it will he too late to do anything. Even as I write there are undoubtedly scores of groups preparing poly water. Scientists everywhere must be alerted to the need for extreme caution in the disposal of poly water. Treat it as the most deadly virus until its safety is established. Yours faithfully, F. j- Dow ah on Pennsylvania 18703, USA. 29 Zvláštnosti vody Denis Rousseau, Bell Labs USA NATURE VOL. 230 MARCH 5 1971 NEWS AND VIEWS PoSywoier Drains Away It now begins to seem as if the concept of polywater is on its last legs. The article by Barnes, Cherry, Finney and Petersen on page 31 of this issue of Nature is one of several recent demonstrations Ihat many of the observations put forward in the past few years as evidence of the existence of an anomalous form of water must be accounted for quite differently and much more trivially. On The fare nf rhinos at least, polvwater seems to he not a distinct, stable (or metastable) form of water, but water stem lo be conspicuous. One uf Hie most striking and direct demonstretions of this was the article by Bascom, Brooks and Warthinglon last year {Nature. 228. 1290: Anomaltll vlaSttlOStl pOlyvOdy 1970), which described how electron probe measurements of the residues obtained by condensing polywater had díky kontaminací Z kapilár revealed the presence of silicon and sodium atoms. The quantities are indeed sufficiently small to explain why a Z potu experimentátorů... the presence of impurities has been unnoticed for so long. This, however, does not fully account for the way in which experimenters in the late nineteen sixties were apparently happy to record observations of anomalously high viscosity and boiling point without subjecting their samples to tie full rigours of modern microanalysis. Studená fůze 1989: S. Pons & M. Fleischmann China's Angry Students IME Vodíková vazba IUPAC: The hydrogen bond is an attractive interaction between a hydrogen atom from a molecule or a molecular fragment X-H in which X is more electronegative than H, and an atom or a group of atoms in the same or a different molecule, in which there is evidence of bond formation. Vodíková vazba • interakce v důsledku přenosu náboje mezi donorem a akceptorem • atomy X a H jsou spojeny kovalentní vazbou, která je polarizovaná - s rostoucí elektronegativitou X roste i síla vazby H...Y • vodíková vazba je obvykle planární- čím více se úhel blíží 180°, tím je vodíková vazba silnější a vzdálenost H...Y menší • při vzniku vodíkové vazby obvykle dochází k nárůstu délky vazby X-H, což se v IR spektroskopii projeví červeným posunem, ale existují i vodíkové vazby, které způsobují modrý nebo žádný posun vibračních frekvencí v IR • vodíková vazba vykazuje charakteristické signatury v NMR spektroskopii • kritérium, že délka vodíkové vazby je menší než součet van der Waalsových poloměrů, neplatí obecně, platí pouze pro silné vodíkové vazby Příklady vodíkové vazby /° H H slabé ji—^ /H \" / °^H--"" ~~ střední R-ev... H °% ..... H -R silné F- -H.............F 34 Směrovost vodíkové vazby -40 -30 -20 -10 0 10 20 30 40 Bond angle, 6 (deg) 35 Potenciální energie vodíkové vazby Hydrogen bond -2.8A- O —H...........O v:j O —H...........O O...........H —O Symetrical hydrogen bond Low-barrier hydrogen bond -2.5A—' O-H------O O......H-0 O—H — O Single-well hydrogen bond Vodíkové vazby v biopolymerech - génom Thymine Adenine 5' end ( y .. ľ7' tf*AJ Phosphate- j> ,■ ■ - iii '"f-v^ í w • deoxyribose0*^ /—\ ^y~/^ backbone "° J \ 3-end Cytosine /"■* Guanine 5 end Vodíkové vazby v biopolymerech - cukry 39