Question

Write the balanced molecular and net ionic equations for the reaction between aluminum metal and silver nitrate. identify the oxidation and reduction half-reactions.

Answer 1

Well in this case, silver nitrate is reduced:

Ag+  +  e−  → Ag(s) ↓

 

Meanwhile, the aluminum is oxidized forming a positive ion:

Al(s)  →  Al3+  +  3e−

 

To get the overall reaction,  we add the half equations so that the electrons are eliminated:

Al(s)  +   3Ag+  →  Al3+  +  3Ag(s)

 

And similarly:

Al(s)  +  3AgNO3(aq)  →  Al(NO3)3(aq)  +  3Ag(s)

Answer 2

The balanced molecular equation is $\boxed{{\text{Al}}\left(s\right)+3{\text{AgN}}{{\text{O}}_3}\left({aq}\right)\to {\text{Al}}{{\left({{\text{N}}{{\text{O}}_{\text{3}}}}\right)}_3}\left({aq}\right)+3{\text{Ag}}\left(s\right)}$

The balanced net ionic equation is $\boxed{{\text{Al}}\left( s\right)+3{\text{A}}{{\text{g}}^+}\left({aq}\right)\to{\text{A}}{{\text{l}}^{3+}}\left({aq}\right)+3{\text{Ag}}\left(s\right)}$

The reduction half-cell reaction is $\boxed{{\text{Ag}}+{e^-}\to{\text{Ag}}}$

The oxidation half-cell reaction is $\boxed{{\text{Al}}\to{\text{A}}{{\text{l}}^{3+}}+3{e^-}}$

Further Explanation:

The three types of equations that are used to represent the chemical reaction are as follows:

1. Molecular equation

2. Total ionic equation

3. Net ionic equation

The reactants and products remain in undissociated form in the molecular equation. In the case of total ionic equation, all the ions that are dissociated and present in the reaction mixture are represented while in the case of overall or net ionic equation only the useful ions that participate in the reaction are represented.

The steps to write the molecular equation and net ionic reaction are as follows:

Step 1: Write the molecular equation for the reaction with the phases in the bracket.

In the reaction,1 mole of Al reacts with 3 moles of ${\text{AgN}}{{\text{O}}_3}$ to form 1 mole of ${\text{Al}}{\left( {{\text{N}}{{\text{O}}_3}} \right)_3}$ and 3 moles of Ag. The balanced molecular equation of the reaction is as follows:

 ${\text{Al}}\left(s\right)+3{\text{AgN}}{{\text{O}}_3}\left( {aq}\right)\to{\text{Al}}{\left( {{\text{N}}{{\text{O}}_{\text{3}}}}\right)_3}\left({aq}\right)+3{\text{Ag}}\left(s\right)$

Step2: Dissociate all the compounds with the aqueous phase to write the total ionic equation. The compounds with solid and liquid phases remain same. The total ionic equation is as follows:

 ${\text{Al}}\left(s\right)+3{\text{A}}{{\text{g}}^+}\left({aq}\right)+{\text{NO}}_3^-\left( {aq}\right)\to{\text{A}}{{\text{l}}^{3+}}\left({aq}\right)+{\text{NO}}_3^-\left({aq}\right)+3{\text{Ag}}\left(s\right)$

Step3. The common ions on both sides of the reaction get cancelled out to get the net ionic equation.

${\text{Al}}\left(s\right)+3{\text{A}}{{\text{g}}^+}\left({aq}\right)+\boxed{{\text{NO}}_3^-\left({aq}\right)}\to{\text{A}}{{\text{l}}^{3+}}\left({aq}\right)+\boxed{{\text{NO}}_3^ - \left({aq}\right)}+3{\text{Ag}}\left(s\right)$

Therefore, the net ionic equation is as follows:

${\text{Al}}\left(s\right)+3{\text{A}}{{\text{g}}^+}\left({aq}\right)\to{\text{A}}{{\text{l}}^{3 + }}\left({aq}\right)+3{\text{Ag}}\left(s\right)$

Redox reaction:

It is a type of chemical reaction in which the oxidation states of atoms are changed. In this reaction, both reduction and oxidation are carried out at the same time. Such reactions are characterized by the transfer of electrons between the species involved in the reaction.

The process of gain of electrons or the decrease in the oxidation state of the atom is called reduction while that of loss of electrons or the increase in the oxidation number is known as oxidation. In redox reactions, one species lose electrons and the other species gain electrons. The species that lose electrons and itself gets oxidized is called as a reductant or reducing agent. The species that gains electrons and gets reduced is known as an oxidant or oxidizing agent. The presence of a redox pair or redox couple is a must for the redox reaction.

The general representation of a redox reaction is,

${\text{X}}+{\text{Y}}\to{{\text{X}}^+}+{{\text{Y}}^-}$

The oxidation half-reaction can be written as:

${\text{X}}\to{{\text{X}}^+}+{e^-}$

The reduction half-reaction can be written as:

${\text{Y}}+{e^-}\to{{\text{Y}}^-}$

Here, X is getting oxidized and its oxidation state changes from  to +1 whereas B is getting reduced and its oxidation state changes from 0 to -1. Hence, X acts as the reducing agent whereas Y is an oxidizing agent.

Ag in silver nitrate forms solid silver during the reaction so it is getting reduced. The reduction half-cell reaction is as follows:

${\text{Ag}}+{e^-}\to{\text{Ag}}$

Aluminium gets converted to ${\text{A}}{{\text{l}}^{3+}}$ by oxidizing itself. The oxidation half-cell reaction is as follows:

${\text{Al}}\to{\text{A}}{{\text{l}}^{3+}}+3{e^-}$

Learn more:

1. Balanced chemical equation: https://brainly.com/question/1405182

2. Oxidation and reduction reaction: https://brainly.com/question/2973661

Answer details:

Grade: High School

Subject: Chemistry

Chapter: Chemical reaction and equation

Keywords: net ionic equation, Ag, Al, NO3-, Al3+, e-, Ag+, redox, oxidizing, reducing, oxidation half-cell reaction, reduction half-cell reaction, molecular equation, AgNO3, Al(NO3)3.