Aqueous solutions strong electrolytes

Electrolytic dissociation in aqueous solution strong electrolytes weak electrolytes. Writing equations for electrode react >ns and over-all reactions. 

As examples of this, fig. 21.7 contains data on the osmotic coefficient of various aqueous solutions strong electrolytes such as NaCl, KCl, and H2SO4 exhibit behaviour (c), while non-electrolytes behave as (6). 

In Chapter 4, we classified solutes by their ability to conduct an electric current, which requires moving ions to be present. Recall that an electrolyte is a substance that dissociates into ions in aqueous solution strong electrolytes dissociate completely, and weak electrolytes dissociate very little. Nonelectrolytes do not dissociate into ions at all. To predict the magnitude of a colligative property, we refer to the solute formula to find the number of particles in solution. Each mole of nonelectrolyte yields 1 mol of particles in the solution. For example, 0.35 M glucose contains 0.35 mol of solute particles per liter. In principle, each mole of strong electrolyte dissociates into the number of moles of ions in the formula unit 0.4 M Na2S04 contains 0.8 mol of Na ions and 0.4 mol of S04 ions, or 1.2 mol of particles, per liter (see Sample Problem 4.1). 

In the case of ISE of electrolytes, one has to take into consideration that in aqueous solutions strong electrolytes dissociate into constituent ions. If only one electrolyte is present in the sample, the cations and anions are forced to move together, even in the case that there is no tendency to form ionic pairs. In this marmer the principle of local electroneutrality is abided by. Obviously, the larger ion that happens to be excluded from the porous space will govern to a greater extent the velocity of the salt zone migration in the column and the final elution volume. The smaller counter ion will probably not retard the zone to a noticeable extent. 

Aqueous solutions of many salts, of the common strong acids (hydrochloric, nitric and sulphuric), and of bases such as sodium hydroxide and potassium hydroxide are good conductors of electricity, whereas pure water shows only a very poor conducting capability. The above solutes are therefore termed electrolytes. On the other hand, certain solutes, for example ethane-1,2-diol (ethylene glycol) which is used as antifreeze , produce solutions which show a conducting capability only little different from that of water such solutes are referred to as non-electrolytes. Most reactions of analytical importance occurring in aqueous solution involve electrolytes, and it is necessary to consider the nature of such solutions. 

In the third period, which ended in 1999 after the book VIG was published, various fluids had been studied strongly polar nonassociated liquids, liquid water, aqueous solutions of electrolytes, and a solution of a nonelectrolyte (dimethyl sulfoxide). Dielectric behavior of water bound by proteins was also studied. The latter studies concern hemoglobin in aqueous solution and humidified collagen, which could also serve as a model of human skin. In these investigations a simplified but effective approach was used, in which the susceptibility % (m) of a complex system was represented as a superposition of the contributions due to several quasi-independent subensembles of molecules moving in different potential wells (VIG, p. 210). (The same approximation is used also in this chapter.) On the basis of a small-amplitude libration approximation used in terms of the cone-confined rotator model (GT, p. 238), the hybrid model was suggested in Refs. 32-34 and in VIG, p. 305. This model was successfully employed in most of our interpretations of the experimental results. Many citations of our works appeared in the literature. 

The Nature of Aqueous Solutions Strong and Weak Electrolytes... 

Solutes that are water-soluble can be classified as either electrolytes or nonelectrolytes. Electrolytes are substances whose aqueous solutions conduct electric current. Strong electrolytes are substances that conduct electricity well in dilute aqueous solution. Weak electrolytes conduct electricity poorly in dilute aqueous solution. Aqueous solutions of nonelectrolytes do not conduct electricity. Electric current is carried through aqueous solution by the movement of ions. The strength of an electrolyte depends on the number of ions in solution and also on the charges on these ions (Figure 4-2). 

It will be observed that in the preceding treatment the assumption has been made that the ion concentration is in each case the same as the total concentration of the electrolyte. That is to say, a degree of dissociation has not been introduced. For this reason the Debye-Huckel theory has been frequently referred to as a theory of complete dissociation. Although the evidence, Chapters 8 and 12, appears to support the assumption that at least in dilute aqueous solutions strong... 

The strength of an acid or base is determined by the extent of its ionization in aqueous solution. Strong acids, such as hydrochloric acid, are 100 percent ionized in aqueous solution, whereas weak acids, such as acetic acid, are less than 5 percent ionized. Experimentally, the extent of ionization is determined by measuring the electrical conductance of solutions. Strong acids and bases are strong electrolytes, and weak acids and bases are weak... 

Electrolytes are substances whose aqueous solutions conduct electric current. Strong electrolytes are substances that conduct electricity well in dilute aqueous solution. Weak electrolytes conduct electricity poorly in dilute aqueous solution. Aqueous solutions of nonelectrolytes do not conduct electricity. 

Electrolytes strong electrolytes, such as NaCI, yield only ions when they dissolve in aqueous solution. Weak electrolytes, such as HF, exist as both ions and unionized molecules in aqueous solution. Nonelectrolytes, such as sucrose, 6 2 22 11 not form any ions in aqueous solution. 

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