Conductance of solutions

The conductivity of solutions depends, from A2.4.31. on both the concentration of ions and their mobility. Typically, for 1 M NaCl in water at 18°C, a value of 7.44 is found by contrast, 1 M H2SO4 has a... 

When an ionic solution contains neutral molecules, their presence may be inferred from the osmotic and thermodynamic properties of the solution. In addition there are two important effects that disclose the presence of neutral molecules (1) in many cases the absorption spectrum for visible or ultraviolet light is different for a neutral molecule in solution and for the ions into which it dissociates (2) historically, it has been mainly the electrical conductivity of solutions that has been studied to elucidate the relation between weak and strong electrolytes. For each ionic solution the conductivity problem may be stated as follows in this solution is it true that at any moment every ion responds to the applied field as a free ion, or must we say that a certain fraction of the solute fails to respond to the field as free ions, either because it consists of neutral undissociated molecules, or for some other reason ... 

The conductivity of solutions is measured as specific conductance, which may be expressed as omhos/cm or mmhos/cm at 25°C. Seawater has a specific conductance of about 50 mmhos/cm. Salinity shows a high correlation with specific conductance at low to moderate TDS levels, but the concentrations of ions in brines are so high that the relationship between concentration and conductance becomes ill-defined.64... 

Sonication of 0.05 M Hg2(N03)2 solution for 10,20 and 30 min and the simultaneous measurements of conductivity, temperature change and turbidity (Table 9.2) indicated a rise in the turbidity due to the formation of an insoluble precipitate. This could probably be due to the formation of Hg2(OH)2, as a consequence of hydrolysis, along with Hg free radical and Hg° particles which could be responsible for increase in the turbidity after sonication. The turbidity increased further with time. Mobility of NO3 ions was more or less restricted due to resonance in this ion, which helped, in the smooth and uniform distribution of charge density over NO3 ion surface. Hence the contribution of NOJ ion towards the electrical conductance was perhaps much too less than the conduction of cationic species with which it was associated in the molecular (compound) form. Since in case of Hg2(N03)2, Hg2(OH)2 species were being formed which also destroyed the cationic nature of Hg22+, therefore a decrease in the electrical conductance of solution could be predicted. The simultaneous passivity of its anionic part did not increase the conductivity due to rise in temperature as anticipated and could be seen through the Table 9.2. These observations could now be summarized in reaction steps as under ... 

Although, there was a net increase in the conductance of solution with increasing duration of sonication, but two opposing factors contributed significantly as under ... 

UV spectra of these solutions were recorded and the concentration of zinc was measured from the absorbance value and the results obtained have been shown in Table 9.11. In another experiment, the nephelometric and conductometric analysis were carried out but only after diluting the solutions from 5 to 1 M of NaOH, since the conductivity of solutions above this concentration was beyond the scale of the conductivity meter. 

K = electrical conductivity of solution Vf = flow rate volume/time of solution through ES capillary y = surface tension of solvent e = permitivity of solvent Co = permitivity of vacuum e/ o = dielectric constant of solvent... 

Figure 7 The effect of diethyl ether on the specific conductivity of solutions of AlCl3 in C2H5Cl (2.5 x 10"2 mole/l) at -78.5°, and on the DP of poly iso butenes formed in...

The effects of the non-polar additives benzene and cyclohexane were compared [69] by studying the effect (at -78.5°) of increasing concentrations of these compounds on the conductivity of solutions of A1C13 and of EtOHAlCl3 in ethyl chloride, and on the DP of the polyisobutenes formed in these solutions. 

Two of the suppositions on which the theory is based-self-ionisation of aluminium chloride, and complexing between aluminium chloride and isobutene-are made by analogy with the facts established for closely related systems. Unfortunately we have here a prime example of the well known fact that the less one knows about a situation, the more one needs to say about it. If reliable measurements on the conductivity of solutions of aluminium chloride in methyl chloride were available, and if we had direct evidence for... 

Electrical Conductivity. A further topic which needs to be considered is the correlation found by Zlamal, Ambroz, and Vesely [2] between the specific conductivity of solutions (mainly in ethyl chloride) of aluminium chloride containing various quantities of a polar compound (acetonitrile, butyraldehyde, ethanol, etc.) and the DP of the polyisobutenes formed in these solutions. Over a certain range of concentrations there is an inverse correlation between the specific conductivity, which has a sharp minimum when the ratio [AlCl3]/[Additive] = 1, and the DP, which at the same composition shows a sharp maximum. 

The role of ion-pairs is discussed at some length. Conductivity measurements on polymerised solutions of EVE with successive dilutions gave results from which ion-pair dissociation constants KD were calculated conventionally by means of Shedlovsky plots. However, since the conductivity of solutions of the model system EtOCHMe+ SbCl6" can be interpreted much more plausibly in terms of a BIE (Plesch and Stannett, 1982),... 

Observing and Inferring The electrical conductivities of solutions of weak acids, such as acetic acid, are related to the degree of ionization of the acid. 

A pH of solution B Mass of solute present C Conductivity of solution... 

The electrical conductivity of solutions is measured for at least three distinct purposes ... 

Fig. 10.17 Electrical conductivity of solutions Na in NH3 at 240 K, due to Kraus (1921). A marks the minimum in conductance per ion pair shown in Fig. 10.15. From Cohen...

The equivalent electrical conductivities of solutions of the alkali chlorides59 containing a mol. of the salt in i litres of water, at 25°, are ... 

Conductivity of Solutions of Symmetrical Strong Electrolytes at Moderate to High Concentrations... 

HYDROGEN BONDING AND THE ELECTRICAL CONDUCTIVITIES OF SOLUTIONS IN SULPHURIC ACID THE MOBILITIES OF THE IONS... 

The specific conductances of solutions of a few representative metal sulphates are shown in Fig. 1. Metal sulphates react completely with... 

The conductivities of solutions of KDS04, and NaBS04 in Da304 were also measured and the equivalent conductivity of die DS04 ion was calculated in a similar manner to that used to obtain HS04. A value of A°D30j/ = 86 was obtained. 

The equivalent conductivities of H3SQ4 and 1)8S04 were obtained from the conductivities of solutions of H2S207 in H2S04 and D2S207 in 1)2804. These acids are partly ionized according bo the equations... 

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