Why space acids weak or strong?Every mountain reacts v water. Once it loser a proton, it transfers that proton come water. Water acts together a base once it solvates the proton. The conjugate acid is protonated water and also it is represented as (H3O)+, (H5O2)+, (H2nOn)+, or simply as H+(aq). The conjugate base is the acid minus that is proton.A solid acid is fully dissociated in water while a weak mountain is in equilibrium v its conjugate base in water. Let"s look in ~ the reaction of a strong acid, nitric acid or HNO3, and a weaker acid, nitrous acid or HNO2, in water.
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Nitric mountain is a more powerful acid 보다 nitrous acid because its conjugate basic is an ext stable. The NO3- ion has excess an adverse charge spread out end 3 oxygen atoms while the excess an adverse charge in NO2- is spread out out over on 2 oxygen atoms.A conjugate base is more stable once the an adverse charge is on one electronegative element and also when the charge is delocalized over multiple atoms. The an ext stable the conjugate base, the more powerful the acid. A stable conjugate base is not really basic. A very solid acid has a an extremely weak conjugate base and also a an extremely weak acid has actually a very strong conjugate base.
Weak acid EquilibriumNitrous mountain is in equilibrium v a proton and its conjugate base, NO2-. Because the concentration of water is constant, we can define a continuous equal to the product of the concentration of water and also the equilibrium constant. This constant, the Ka is 10-3.29 because that HNO2.
We have the right to use the Ka to recognize the pH the a systems of nitrous acid. Because that example, let"s recognize the pH that a solution made native 0.01 mole the HNO2 in 1.0 together of water. Some of the acid will dissociate right into H+ and NO2- yet we don"t recognize w=how much. We"ll contact the molar concentration that solvated protons x therefore
It is always possible to deal with for x by using the quadratic equation but most of the moment we have the right to solve it utilizing an approximation. If we assume the the level of dissociation is small, then the equilibrium concentration of acid doesn"t change very much from its initial concentration. We have the right to then use the initial acid concentration in the Ka expression.The approximation is a an excellent one in this case due to the fact that we obtain the very same pH value utilizing it as we did from the quadratic equation.
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