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For each solute listed, write the chemical equation for the dissociation of the

ID: 825298 • Letter: F

Question

For each solute listed, write the chemical equation for the dissociation of the salt into its ions. If the salt is acidic, write the chemical equation for the reaction of the acidic ion in water to produce hydronium ion, write the expression for the acid ionization constant, Ka, and calculate the value of Ka.


If the salt is basic, write the chemical equation for the reaction of the basic ion with water to produce hydroxide ion, write the expression for the base ionization constant, Kb, and calculate the value of Kb from your data.

Solute

Chemical equations

Expression for Kb or Ka

Value of Kb or Ka

NaC2H3O2

Na2SO4

NaHSO4

Na2CO3

NH4Cl


Solute

Chemical equations

Expression for Kb or Ka

Value of Kb or Ka

NaC2H3O2

Na2SO4

NaHSO4

Na2CO3

NH4Cl

Explanation / Answer

NaC2H3O2 --> Na + C2H3O2-

then C2H3O2- + H2O <--> HC2H3O2 + OH-

Kb = [HC2H3O2 ][OH-]/[C2H3O2]

Kb = Kw/Ka = (10-14)/1.8*10^-5) = 5.55*10^-10

Na2SO4

2NA +´SO4-2

SO4-2 + H2O <--> HSO4- + OH-

Kb = [HSO4-][OH-]/[SO4-2]

Kb = Kw/Ka = (10^-14)/(1.2*10^-2) = 8.33*10^-13

NaHSO4

NaHSO4 --> Na+ + HSO4-

HSO4- <--> H+ + SO4-2

Ka = [H+][SO4-2]/[HSO4-]

1.2*10^-2 = [H+][SO4-2]/[HSO4-]

Na2CO3

Na2cO3 --< 2Na+ + CO3-2

CO3-2 + H2O <--> HCO3- + OH-

Kb2 = Kw/Ka2 = (10^-14)/(4.8*10^-11) = 2.08*10^-4

NH4Cl

NH4+ + Cl-

NH4+ --> NH3 + H+

Ka = [NH3][H+]/[NH4+]

Ka = Kw/Kb = (10^-14)/(1.8*10^-5 = 5.55*10^-10

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