[mintsharpie]

I'm having trouble with identifying whether a solution is acidic, basic or neutral. I have no idea what steps I should take. Are there calculations involved, or is it just an assumption based on logic?

I've included a few examples from my textbook, if someone would like to help me with any of these.

1. (NH₄)₃PO_4(aq)

2. (NH₄)₂SO_4(aq)

3. MgO_(aq)

[Lone Proton]

I'm having trouble with identifying whether a solution is acidic, basic or neutral. I have no idea what steps I should take. Are there calculations involved, or is it just an assumption based on logic?

I've included a few examples from my textbook, if someone would like to help me with any of these.

1. (NH₄)₃PO_4(aq)

2. (NH₄)₂SO_4(aq)

3. MgO_(aq)

Numbers 1 and 2 are Acidic because when NH₄ is an acid. It is an acid because the NH₄ should really only be holding 3 hydrogens, but does hold an extra one, to make it acidic.

Number 3 is debatable, but i would say it is basic becuase the Oxygen could grap a hydrogen and thats OH - very basic.

[Borek]

Numbers 1 and 2 are Acidic because when NH₄ is an acid. It is an acid because the NH₄ should really only be holding 3 hydrogens, but does hold an extra one, to make it acidic.

1 is slightly basic. While you are right about NH₄⁺ being a weak acid, PO₄^3- - being a conjugate base of a very weak acid - is a relatively strong base.

But that's not easy to judge without calculations.