Balance the equation:
NO2- (aq) + Al (s) --> NH3 (g) + AlO2- (aq) (basic solution)
** please note the "2-" on the NO2- and AlO2- are not subscripts, they are the charges.
I missed a few classes in Chemistry and find myself lost. I have tried to learn these equations with the steps but I am still not able to solve them. Please show work when answering. Thank you so much!
I don't think that equation is correct. For AlO^2- to be correct means Al must be zero and there is no redox when Al(s) goes to AlO^2- since Al is zero in that anion. Same for NO^2-. I might believe [AlO2]^- and [NO2]^-
1. Al ==> [AlO2]^-
2. Assign oxidation states and add electrons to balance the change.
Al is zero on left and +3 on the right.
Al ==> [AlO2]- + 3e
3. Count the charges on each side (zero on left and -4 on the right; add OH^- to balance the charge.
Al + 4OH^- ==> [AlO2]^- + 3e
4. Now add H2O to the appropriate side to balance the H.
Al + 4OH^- ==> [AlO2]^- + 3e + 2H2O
The NO2^- is done the same way.
To balance the equation, we need to make sure that the number of atoms on both sides of the equation is equal. Here's how you can balance it step-by-step:
Step 1: Separate the equation into half-reactions.
NO2- (aq) → NH3 (g)
Al (s) → AlO2- (aq)
Step 2: Balance the non-hydrogen and non-oxygen atoms first.
Balancing the nitrogen (N) atoms:
On the left side, there is 1 nitrogen atom in NO2-. On the right side, there is 1 nitrogen atom in NH3.
The nitrogen atoms are already balanced.
Balancing the aluminum (Al) atoms:
On the left side, there is 1 aluminum atom in Al. On the right side, there is 1 aluminum atom in AlO2-.
The aluminum atoms are already balanced.
Step 3: Balance the oxygen (O) atoms by adding water (H2O).
On the left side, there are 2 oxygen atoms in NO2-. To balance this, we need to add 2 water molecules (H2O) to the right side of the equation.
NO2- (aq) → NH3 (g)
2H2O (l)
Now, we have:
Balancing the oxygen (O) atoms:
On the left side, there are 2 oxygen atoms in NO2-. On the right side, there are 2 oxygen atoms in the 2 water molecules.
The oxygen atoms are balanced.
Step 4: Balance the hydrogen (H) atoms by adding hydrogen ions (H+).
On the left side, there are no hydrogen atoms. To balance this, we need to add 2 hydrogen ions (H+) to the left side of the equation.
2H+ (aq) + NO2- (aq) → NH3 (g) + 2H2O (l)
Now, we have:
Balancing the hydrogen (H) atoms:
On the left side, there are 2 hydrogen atoms in the 2 hydrogen ions (H+). On the right side, there are 2 hydrogen atoms in the water molecules.
The hydrogen atoms are balanced.
Step 5: Balance the charges by adding electrons (e-).
On the left side, there is a charge of -1 on the NO2- ion. To balance this, we need to add 1 electron (e-) to the left side of the equation.
e- + 2H+ (aq) + NO2- (aq) → NH3 (g) + 2H2O (l)
Now, we have:
Balancing the charge:
On the left side, there is a charge of -1 on the NO2- ion. On the right side, there are no charges.
The charge is balanced.
Step 6: Combine the half-reactions and simplify the equation.
To combine the half-reactions, we need to multiply the oxidation half-reaction by 2 and the reduction half-reaction by 1.
2e- + 4H+ (aq) + 2NO2- (aq) → 2NH3 (g) + 4H2O (l)
Al (s) → AlO2- (aq)
Now, the equation is balanced!
Final balanced equation (in basic solution):
2Al (s) + 2NO2- (aq) + 6H2O (l) → 2NH3 (g) + 2AlO2- (aq) + 8OH- (aq)
To balance the given chemical equation in a basic solution, you need to follow these steps:
Step 1: Identify the atoms and elements in the equation. In this case, we have:
Reactants: NO2- (aq), Al (s)
Products: NH3 (g), AlO2- (aq)
Step 2: Begin by balancing the least abundant or most complex atoms. In this case, let's start with nitrogen (N).
Reactants: NO2- (aq) + Al (s)
Products: NH3 (g) + AlO2- (aq)
Since there is only one nitrogen atom on the reactant side and one on the product side, nitrogen is already balanced.
Step 3: Move on to balancing other elements, starting with oxygen (O). Identify which element contains oxygen in the equation.
Reactants: NO2- (aq) + Al (s)
Products: NH3 (g) + AlO2- (aq)
On the reactant side, we have two oxygen atoms in NO2-. On the product side, we have only one oxygen atom in NH3. This implies that we need to balance the oxygen atoms by adding OH- ions to one of the sides.
Reactants: NO2- (aq) + Al (s)
Products: NH3 (g) + AlO2- (aq) + OH- (aq)
To balance oxygen, we add one OH- ion to the reactant side:
NO2- (aq) + Al (s) + OH- (aq) → NH3 (g) + AlO2- (aq) + OH- (aq)
Now we have 2 oxygen atoms on each side.
Step 4: Next, balance the hydrogen (H) atoms. Identify which compound contains hydrogen in the equation.
Reactants: NO2- (aq) + Al (s) + OH- (aq)
Products: NH3 (g) + AlO2- (aq) + OH- (aq)
We have 3 hydrogen atoms in NH3 on the product side, but no hydrogen atoms on the reactant side. To balance hydrogen, we add 3 H2O molecules to the reactant side:
NO2- (aq) + Al (s) + OH- (aq) + 3H2O (l) → NH3 (g) + AlO2- (aq) + OH- (aq)
Step 5: Finally, balance the charges. This step is necessary in a basic solution. Calculate the total charge on each side of the equation.
Reactant charge: -1 (NO2-) + 0 (Al) - 1 (OH-) = -2
Product charge: 0 (NH3) - 1 (AlO2-) - 1 (OH-) = -2
The charges are already balanced.
The balanced equation in a basic solution is:
NO2- (aq) + Al (s) + OH- (aq) + 3H2O (l) → NH3 (g) + AlO2- (aq) + OH- (aq)
Please note that balancing equations requires practice, and it's essential to understand the concepts of oxidation numbers, conservation of mass, and charge balancing.