Q4.47 - Chemistry: Molecular Nature Of Matter And Change

Question

Que Complete the following acid-base reactions with balanced molecular, total ionic, and net ionic equations: 

(a) Potassium hydroxide(aq) + hydrobromic acid(aq) 

(b) Ammonia(aq) + hydrochloric acid(aq)

Step-by-Step Solution

Answer

Answer

 

The acid-base reactions with a balanced molecular equation is:

(a)  $\mathrm{KOH}\left(\mathrm{aq}\right)+\mathrm{HBr}\left(\mathrm{aq}\right)\to \mathrm{KBr}\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{I}\right)$

(b)  ${\mathrm{NH}}_3\left(\mathrm{aq}\right)+\mathrm{HCI}\left(\mathrm{aq}\right)\to {\mathrm{NH}}_4\mathrm{CI}\left(\mathrm{aq}\right)$

 

Step 1: Determine different types of equations to represent aqueous ionic reactions

The molecular equation reveals the least about the species in solution and is actually somewhat misleading because it shows all the reactants and products as if they were intact undissociated compounds.

The total ionic equation is a much more accurate representation of the reaction because it shows all the soluble ionic substances dissociated into ions.

The net ionic equation is the most useful because it omits the spectator ions and shows the actual chemical change taking place.

Step 2: Write the net ionic equation of the reaction between potassium hydroxide and hydrobromic acid

(a)Balanced molecular reaction:

$\mathrm{KOH}\left(\mathrm{aq}\right)+\mathrm{HBr}\left(\mathrm{aq}\right)\to \mathrm{KBr}\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{I}\right)$

 Total ionic reaction:

${\mathrm{K}}^{+}\left(\mathrm{aq}\right)+{\mathrm{OH}}^{-}{\left(\mathrm{aq}\right)}^{+}{\mathrm{H}}^{+}\left(\mathrm{aq}\right)+{\mathrm{Br}}^{-}\left(\mathrm{aq}\right)+{\mathrm{Br}}^{-}\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{I}\right)$

 

Net ionic reaction:

 ${\mathrm{H}}^{+}\left(\mathrm{aq}\right)+{\mathrm{OH}}^{-}\left(\mathrm{aq}\right)\to {\mathrm{H}}_2\mathrm{O}$

 

Step 3: Write the net ionic equation of the reaction between ammonia and hydrochloric acid

b) Balanced molecular reaction:

${\mathrm{NH}}_3\left(\mathrm{aq}\right)+\mathrm{HCI}\left(\mathrm{aq}\right)\to {\mathrm{NH}}_4\mathrm{CI}\left(\mathrm{aq}\right)$

 

Total ionic reaction:

${\mathrm{NH}}_3\left(\mathrm{aq}\right)+{\mathrm{H}}^{+}\left(\mathrm{aq}\right)+{\mathrm{CI}}^{-}\left(\mathrm{aq}\right)\to {\mathrm{NH}}_4\mathrm{CI}\left(\mathrm{aq}\right)$

 

Net ionic reaction:

${\mathrm{NH}}_3\left(\mathrm{aq}\right)+{\mathrm{H}}^{+}\left(\mathrm{aq}\right)\to {{\mathrm{NH}}^{+}}_4\left(\mathrm{aq}\right)$