Question

the chemical formulae of some acids 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.

Explanation:

Step1: Analyze strong acid \( \ce{HClO3} \)

Strong acids completely dissociate in water. \( \ce{HClO3(aq)
ightarrow H+(aq) + ClO3-(aq)} \). So the species are \( \ce{H+} \), \( \ce{ClO3-} \).

Step2: Analyze weak acid \( \ce{HF} \)

Weak acids partially dissociate. \( \ce{HF(aq)
ightleftharpoons H+(aq) + F-(aq)} \), and \( \ce{HF} \) itself is also present in significant amount. So the species are \( \ce{HF} \), \( \ce{H+} \), \( \ce{F-} \).

Step3: Analyze weak acid \( \ce{HClO} \)

Weak acid \( \ce{HClO(aq)
ightleftharpoons H+(aq) + ClO-(aq)} \), and \( \ce{HClO} \) is present. So the species are \( \ce{HClO} \), \( \ce{H+} \), \( \ce{ClO-} \).

Step4: Analyze strong acid \( \ce{HBr} \)

Strong acid \( \ce{HBr(aq)
ightarrow H+(aq) + Br-(aq)} \). So the species are \( \ce{H+} \), \( \ce{Br-} \).

Answer:

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