Final answer:
pH of Solutions The incorrect statement is 'A solution of sodium phosphate will have a pH of less than 7', as such a solution is actually basic and will have a pH greater than 7. The others are correctly identified as neutral or acidic.
Step-by-step explanation:
The statement that 'A solution of sodium phosphate will have a pH of less than 7' is incorrect. Sodium phosphate is a salt of a strong base (sodium hydroxide) and a weak acid (phosphoric acid). As such, a solution of sodium phosphate is basic and will have a pH greater than 7.
For the other substances: a solution of potassium bromide is neutral and will have a pH of 7, because both potassium and bromide ions are from strong acids and bases,
so they do not affect the pH of the solution; a solution of ammonium chloride is acidic (pH less than 7) since ammonium ion is the conjugate acid of ammonia, a weak base; a solution of cobalt(II) chloride is also acidic (pH less than 7) because cobalt(II) ion hydrolyzes to a slight extent,
generating H3O+; and a solution of ammonium fluoride will be acidic because the ammonium ion is a stronger acid than fluoride ion is a base.
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