Question

2.) Which one of the following salts, when dissolved in water, produces the solution with the highest pH?A) NaI B) NaBr C) NaCl D) NaF E) NH4I  F) NH4Br G) NH4Cl H) NH4F

Answer 1

The solution which prodcue more number of OH- ions , will have highest pH .

so check for the most basic solution .

i. A) NaI B) NaBr and C) NaCl are salt of strong acid and strong base. so they are neutral

so the pH of solution will be 7.0 only .

ii.  E) NH4I  F) NH4Br G) NH4Cl H) NH4F are salt of strong acid and weak base NH3.

so they all are acidic salts.

so their pH will be less than seven

iii. The remaining one is NaF

NaF is formed by weak acid HF and Strong base NaOH

HF (aq) + NaOH (aq) ------> NaF (aq ) + H2O (aq)

We know the salt of storng base and weak acid is Basic salt

the pH of Basic salt is greater than seven , and it will the highest of the given all salts

so Answer is NaF (D)