Question

Which is the correct net ionic equation for the following reaction: H3PO4 (aq) + 3 LiOH (aq) > Li3PO4 (aq) + 3 H2O (l)?

1.)H3PO4 (aq) + 3 OH_ (aq) >PO4_3 (aq) + 3 H2O (l)
2.)H3PO4 (aq) >PO4_3 (aq) + 3 H2O (l)
3.)3 LiOH (aq) + 3 H+ (aq) >Li+ (aq) + 3 H2O (l)
4.)H3PO4 (aq) + 3 LiOH (aq) >Li3PO4 (aq) + 3 H2O (l)
what is the correct net ionic equation for the following reaction: 2 HBr (aq) + Co(OH)2 (aq) >CoBr2 (aq) + 2 H2O (l)?
1.)2 H+ (aq) + Co(OH)2 (aq) >Co+2 (aq) + 2 H2O (l)
2.)Co(OH)2 (aq) >Co+2 (aq) + OH− (aq)
3.)H+ (aq) + OH− (aq) >H2O (l)
4.)2 HBr (aq) + Co(OH)2 (aq) >CoBr2 (aq)+2H2O(l)

Answer 1

Answer: The correct option for the chemical equation
`H_3PO_4(aq.)+3LiOH(aq.)\rightarrow Li_3PO_4(aq.)+3H_2O(l)` is 1.

The correct option for the chemical equation
`2HBr(aq.)+Co(OH)_2(aq.)\rightarrow CoBr_2(aq.)+2H_2O(l)` is 3.

Step-by-step explanation:

• For the chemical equation:

`H_3PO_4(aq.)+3LiOH(aq.)\rightarrow Li_3PO_4(aq.)+3H_2O(l)`

`H_3PO_4` is a weak acid and hence will not dissociate into ions whereas LiOH is a strong base and will easily dissociate into ions.

The product
`Li_3PO_4` is soluble in water and hence, will dissociate into its respective ions. Hence, the ionic equation for this reaction is:

`H_3PO_4(aq.)+3Li^(3+)(aq.)+3OH^-(aq.)\rightarrow 3Li^(3+)(aq.)+PO_4^(3-)(aq.)+3H_2O(l)`

Net ionic equation becomes:

`H_3PO_4(aq.)+3OH^-(aq.)\rightarrow PO_4^(3-)(aq.)+3H_2O(l)`

So, the correct option is 1.

• For the chemical equation:

`2HBr(aq.)+Co(OH)_2(aq.)\rightarrow CoBr_2(aq.)+2H_2O(l)`

HBr and
`Co(OH)_2` are strong acid and strong base respectively, hence they will easily dissociate into ions.

The product,
`CoBr_2` is is soluble in water and hence, will dissociate into its respective ions. Hence, the ionic equation for this reaction is:

`2H^+(aq.)+2Br^-(aq.)+Co^(2+)(aq.)+2OH^-(aq.)\rightarrow Co^(2+)(aq.)+2Br^-(aq.)+H_2O(l)`

The net ionic equation becomes:

`H^+(aq.)+OH^-(aq.)\rightarrow H_2O(l)`

So, the correct option is 3.