Question

1.What will happen when you add ammonium hydroxide to sodium hydroxide?

2.Explain why acetic acid and sodium acetate can exist in an equilibrium but hydrochloric acid and sodium hydroxide cannot.

3.How will cobalts equilibrium with 1M HCL differ from its equilibrium with concentrated H2SO4?

Answer 1

1) The NH4OH is ammonia gas (NH3), dissolved in agua.Es quite unstable in strong bases such as NaOH, so if you put the strong base in NH4OH solution gaseous NH3 is released. So the net equation is: NH4OH (aq) -----> NH3(g) + H2O(l)

2) Because the acetic acid and acetate are a couple "acid / base conjugate" which can coexist in equilibrium (the "sodium acetate" is acetic acid salt); while hydrochloric acid and sodium hydroxide are acid and base without relationship between them, both stronger than react to form a salt (NaCl).

3) With HCL:

*The two different coloured Co(II) complex ions, [Co(H₂O)₆]²⁺ and [CoCl₄]^2-, exist together in equilibrium in solution in the presence of chloride ions: [Co(H₂O)₆]²⁺(aq)(pink) + 4Cl^-(aq) ⇌ [CoCl₄]^2-(aq)(blue) + 6H₂O(l)

With H2SO4:

*Cobalt metal dissolves slowly in dilute sulphuric acid to form solutions containing the aquated Co(II) ion together with hydrogen gas, H₂. In practice, the Co(II) is present as the complex ion [Co(OH₂)₆]²⁺: Co(s) + H₂SO₄(aq) → Co²⁺(aq) + SO₄^2-(aq) + H₂(g)