(Solved): 5. \[ \mathrm{HOBr}(a q) \rightleftarrows \mathrm{H}^{+}(\mathrm{aq})+\mathrm{OBr}(a q) \] Hypobrom ...

5. \[ \mathrm{HOBr}(a q) \rightleftarrows \mathrm{H}^{+}(\mathrm{aq})+\mathrm{OBr}(a q) \] Hypobromous acid, HOBr, is a weak acid that dissociates in water, as represented by the equation above. (a) Calculate the value of \( \left[\mathrm{H}^{*}\right] \) in an \( \mathrm{HOBr} \) solution that has a \( \mathrm{pH} \) of \( 4.95 \). (b) Write the equilibrium constant expression for the ionization of \( \mathrm{HOBr} \) in water, then calculate the. concentration of \( \mathrm{HOBr}(a q) \) in an \( \mathrm{HOBr} \) solution that has \( \left[\mathrm{H}^{*}\right] \) equal to \( 1.8 \times 10^{-5} \mathrm{Mf}_{\text {. }} \) (c) A solution of \( \mathrm{Ba}(\mathrm{OHD} \), is titrated into a solution of \( \mathrm{HOBr} \). (i) Calculate the volume of \( 0.115 \mathrm{M} \mathrm{Ba}(\mathrm{OH})_{2}(a q) \) needed to reach the equivalence point when titrated into a \( 65.0 \mathrm{~mL} \) sample of \( 0.146 \mathrm{Mf} \mathrm{HOBr(aq)} \). (ii) Indicate whether the pH at the equivalence point is less than 7, equal to 7. or greater than 7. Explain. (d) Calculate the number of moles of \( \mathrm{NaOBr}(\mathrm{s}) \) that would have to be added to \( 125 \mathrm{~mL} \) of \( 0.160 \mathrm{M} \) HOBr to produce a buffer solution with \( \left[\mathrm{H}^{*}\right]=5.00 \times 10^{-9} \mathrm{M} \). Assume that volume change is negligible. e) \( \mathrm{HOBr} \) is a weaker acid than \( \mathrm{HBrO}_{3} \). Account for this fact in terms of molecular structure.