Question

the chemical formulae of some adds are listed in the first column of the table below, and in the second column it says whether each acid is strong or weak. complete the table. list the chemical formula of each species present at concentrations greater than about 10^{-6} mol/l when about a tenth of a mole of the acid is dissolved in a liter of water. acid strong or weak? species present at 10^{-6} mol/l or greater when dissolved in water hclo_{3} strong hf weak hclo weak hbr strong

Explanation:

Step1: Analyze strong acid \(HClO_3\)

Strong acids dissociate completely in water. The dissociation reaction of \(HClO_3\) is \(HClO_3
ightarrow H^{+}+ClO_3^{-}\). Also, water auto - ionizes \(H_2O
ightleftharpoons H^{+}+OH^{-}\), but since \(HClO_3\) is a strong acid and its concentration (\(0.1\ mol/L\)) is much larger than \(10^{- 6}\ mol/L\), the species with concentration \(\geq10^{-6}\ mol/L\) are \(H^{+},ClO_3^{-}\) (from \(HClO_3\) dissociation) and \(H_2O\) (solvent, present in large amount).

Step2: Analyze weak acid \(HF\)

Weak acids dissociate partially. The dissociation reaction is \(HF
ightleftharpoons H^{+}+F^{-}\), and water auto - ionizes \(H_2O
ightleftharpoons H^{+}+OH^{-}\). The major species (concentration \(\geq10^{-6}\ mol/L\)) are \(HF\) (undissociated acid, since it is weak), \(H^{+}\), \(F^{-}\) and \(H_2O\).

Step3: Analyze weak acid \(HClO\)

For the weak acid \(HClO\), the dissociation reaction is \(HClO
ightleftharpoons H^{+}+ClO^{-}\), and water auto - ionizes \(H_2O
ightleftharpoons H^{+}+OH^{-}\). The species with concentration \(\geq10^{-6}\ mol/L\) are \(HClO\) (undissociated acid), \(H^{+}\), \(ClO^{-}\) and \(H_2O\).

Step4: Analyze strong acid \(HBr\)

Strong acid \(HBr\) dissociates completely: \(HBr
ightarrow H^{+}+Br^{-}\). Along with water (\(H_2O\)), the species with concentration \(\geq10^{-6}\ mol/L\) are \(H^{+},Br^{-},H_2O\).

Answer:

acid	strong or weak?	species present at \(10^{-6}\ mol/L\) or greater when dissolved in water
\(HF\)	weak	\(HF,H^{+},F^{-},H_2O\)
\(HClO\)	weak	\(HClO,H^{+},ClO^{-},H_2O\)
\(HBr\)	strong	\(H^{+},Br^{-},H_2O\)