What is the molecular and net ionic equation of barium hydroxide and hydrocyanic acid?

Answer 1

Step 1: Write the balanced "molecular" equation:

2 HI + Ba(OH)2 BaI2 + 2H2O

Step 2: Consult the solubility rules linked above to determine whether each substance will dissociate:

2 HI+

Ba(OH)2

BaI2+2 H2O

yes

yes

yes

Step 3: Dissociate all soluble salts, strong acids, and strong bases (except calcium hydroxide). Leave together all "not soluble" salts and weak acids or bases. Note that when H3O+ loses a proton, a water molecule is formed.

2H3O+ (aq) + 2I- (aq) + Ba2+ (aq) + 2OH- (aq)Ba2+ (aq) + 2I- (aq) + 4 H2O (l)

Step 4: Cross out "spectator ions" that appear on both sides of the reaction (these ions do not participate in the chemistry) and rewrite the "net" reaction using the smallest possible coefficients.

H3O+ (aq) + OH- (aq) 2 H2O (l)

Answer 2

The regular reaction equation is: 2HCN + Ba(OH)2 --> Ba(CN)2 + 2H2O.

The full ionic equation is: 2H+(aq) + 2CN-(aq) + Ba+2(aq) + 2OH-(aq) --> Ba(CN)2(s) + H2O(l)

The net ionic equation is: Ba+2(aq) + 2CN-(aq) --> Ba(CN)2(s)

Notes: - the original reaction equation is an acid-base reaction, which is really a subset of double replacement reactions where the reactants are an acid and a base; and the products are water and a salt.

- in the ionic equations, the product barium cyanide, Ba(CN)2, is an insoluble salt, which is why it is expressed as a solid and not its constituent ions.

- the net ionic equation only features the ions which form the precipitate on the left and the precipitate itself on the right. We've cancelled out spectator (water soluble) ions and liquid water.

- hydrocyanic acid, HCN, is a weak acid, and therefore it does not dissociate completely in solution, even though we've shown it that way.

Answer 3

The reaction is:
Ba2+ + 2 (OH)- + 2 H+ + 2 I- = Ba2+ + 2 I- + 2 H2O(liquid)

Answer 4

The molecular equation of barium hydroxide and hydrocyanic acid is Ba(OH)2 + 2HCN -> Ba(CN)2 + 2H2O. The net ionic equation is Ba^2+ + 2OH- + 2HCN -> Ba(CN)2 + 2H2O.