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The Chemical Composition of Aqueous Solutions

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The Chemical Composition of Aqueous Solutions
THE CHEMICAL COMPOSITION OF AQUEOUS SOLUTIONS (pp. 94-98) Electrolytes – forms ions when dissolved in water (or certain other solvents) and thus produce solutions that conduct electricity. Strong electrolytes – ionize essentially completely Weak electrolytes – ionize only partially Solution of weak electrolyte will be a poorer conductor than a solution containing an equal concentration of a strong electrolyte Brønsted-Lowry theory Acid is a proton donor Base is a proton acceptor H2O + HNO2 H3O+ + NO2-

The conjugate base of the acid HNO2 is nitrite ion. The conjugate acid of water is the hydrated proton written as H3O+ Amphiprotic solvent – solvent that can act either as an acid or as a base, a classic example is water. The weakest acid forms the strongest conjugate base The tendency of a solvent to accept or donate protons determines the strength of a solute acid or base dissolved in it.

Conjugate base- the result when an acid gives up a In differentiating solvents, various acids dissociate proton to different degrees and thus have different acid 1 base1 + proton strengths. In a leveling solvent, several acids are completely dissociated and are thus of the same Conjugate acid - the result when a base accepts a strength. proton base2 + proton acid2 For example, perchloric and hydrochloric acids are strong acids in water. If anhydrous acetic acid, a weaker proton acceptor than water, is substituted as the solvent, neither of these acids undergoes complete dissociation

Many solvents are proton donors or proton acceptors and can thus induce basic or acidic behavior in solutes dissolved in them. For example, in an aqueous solution of ammonia, water can Acetic acid acts as a differentiating solvent toward donate a proton and thus acts as an acid with the two acids by revealing inherent differences in respect to the solute: their acidities. Water on the other hand is a leveling solvent for perchloric and hydrochloric NH3 + H2O NH4+ +OHacids because all are

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