Question

questions 32-36 please

32. Write the charge balance equation for a 0.3 M Li2HPO4 salt solution. 33. Write the mass balance equations for a solution of 0.4 M KHCO3 and 0.5 M Na2CO3. 34. What volume of 0.369 M sodium hydroxide is required to titrate 50.00 mL of 0.654 M HBr(ag), hydrobromic acid, to the equivalence point? 35. A 25.00 mL sample of 0.100 M acetic acid is titrated with 0.050 M NaOH. Consider the titration curve, and predict the main chemical species present after adding 15.00 ml NaOH titrant. Example choices More acetic acid than acetate ion; Equal amounts of acetic acid and acetate ion; More acetate ion than acetic acid; Mainly acetate ion; Mainly the excess OH' titrant 36. A 25.00 mL sample of 0.100 M acetic acid is titrated with 0.050 M NaOH. Consider the titration curve, and predict the main chemical species present after adding 50.00 ml NaOH titrant. Example choices More acetic acid than acetate ion; Equal amounts of acetic acid and acetate ion; More acetate ion than acetic acid; Mainly acetate ion; Mainly the excess OH titrant finantator to

Answer 1

The charge balance equation of any aqueous solution is represented by,

n₁[A₁] + n₂[A₂] + ...... = m₁[B₁] + m₂[B₂] + ....

where,

A = concentration of all positively charged ions in the solution

n = magnitude of positive charge

B = concentration of all negatively charged ions in the solution

m = magnitude of negative charge

Hence, the possible equilibrium reaction for Li₂HPO₄ salt solution are as follows:

$Li_{}2HPO_{}4 \leftrightarrow 2 Li^{+} + HPO_{4}^{2-}$

$H_{}3PO_{}4 \rightleftharpoons H^{+} + H_{2}PO_{4}^{-}$

$H_{}2PO_{4}^{-} \rightleftharpoons H^{+} + HPO_{4}^{2-}$

$HPO_{4}^{2-} \rightleftharpoons H^{+} + PO_{4}^{3-}$

$H_{2}O \rightleftharpoons H^{+} + HO^{-}$

with the help of the above equations, the charge-balanced equation for 0.3 M Li₂HPO₄ is

$H^{+} + Li^{+} = [H_{2}PO_{4}^{-}] + 2[HPO_{4}^{2-}] + 3[PO_{4}^{3-}] + [OH^{-}]$