pH question (1 Viewer)

[bEAbEA]

This question appeared in my trial paper, and i just wanted to know what others might have answered for it:

The table below shows the pH of some common salt solutions:
Salt Solution pH
Ammonium nitrate 4.8
Sodium ethanoate 9.1
Sodium chloride 7.0
Showing appropriate equations as support, explain the resulting pH of each salt solution

Any feedback would be appreciated.

 

[Dreamerish*~]

Ammonium Nitrate: NH_3(aq) + HNO_3(aq) → NH₄NO_3(aq)

NH₃ is a weak base while HNO₃ is a strong acid. The strength of the conjugate acid of NH₃ (that is, NH₄⁺) is stronger than the strength of the conjugate base of HNO₃ (that is, NO₃^-). Therefore the salt solution is acidic.

Sodium Ethanoate: NaOH_(aq) + CH₃COOH_(aq) → NaCH₃COO_(aq) + H₂O_(l)

NaOH is a strong base while CH₃COOH is a weak acid. The strength of the conjugate base of CH₃COOH (that is, CH₃COO^-) is stronger than the strength of the conjugate acid of NaOH (that is, NaOH₂⁺). Therefore the salt solution is basic.

Sodium Chloride: NaOH_(aq) + HCl_(aq) → NaCl_(aq) + H₂O_(l)

NaOH is a strong base while HCl is a strong acid. Both conjugates are very slightly acidic and basic (respectively), therefore they "cancel each other out", resulting in a neutral salt solution.

 

[bEAbEA]

thankyou very much