The redox reaction below occurs in acidic solution. Balance it with the smallest whole number coefficients and determine the coefficient for H+. MnO4-(aq) + HNO2(aq) ---> Mn2+(aq) + NO3-(aq)

when i did it..i got the answer as1...but im not to sure..help?

1. 3
2. 5
3. 1
4. 4
5. 2

User Icon for DrBob222 DrBob222 answered
14 years ago

How can you not be too sure? The equation is either balanced or it isn't and you know when you finish if it is right or not. I get 1 H^+ too. And I know that's right because the equation balances

1. atoms.
2. charge.
3. electron change.

User Icon for Anonymous Anonymous answered
8 years ago

Balance this equation in acidic solution Mno-4+Clo3=Clo4+Mn2+

User Icon for Step-by-Step Bot Step-by-Step Bot answered
1 year ago

To balance this redox reaction in acidic solution, follow these steps:

Step 1: Assign oxidation numbers to each element in the reaction. Let's identify the changes:

MnO4- (aq) + HNO2 (aq) → Mn2+ (aq) + NO3- (aq)

The oxidation number of Mn in MnO4- is +7, and in Mn2+ it is +2.
The oxidation number of H in HNO2 is +1, and in NO3- it is +5.

Step 2: Split the reaction into two half-reactions, one for oxidation and one for reduction.

Oxidation half-reaction: MnO4- (aq) → Mn2+ (aq)
Reduction half-reaction: HNO2 (aq) → NO3- (aq)

Step 3: Balance the atoms in each half-reaction.

For the oxidation half-reaction:
MnO4- (aq) → Mn2+ (aq)

We see that we need 4 O on the right side of the equation, so we add 4 H2O on the left side:
MnO4- (aq) + 4 H2O → Mn2+ (aq)

For the reduction half-reaction:
HNO2 (aq) → NO3- (aq)

We see that we need 3 O on the right side of the equation, so we add 3 H2O on the left side:
HNO2 (aq) + 3 H2O → NO3- (aq)

Step 4: Balance the charges in each half-reaction by adding electrons (e-) as necessary.

For the oxidation half-reaction:
MnO4- (aq) + 4 H2O → Mn2+ (aq) + 8 e-

For the reduction half-reaction:
HNO2 (aq) + 3 H2O → NO3- (aq) + 2 e-

Step 5: Multiply the half-reactions by appropriate integers so that the number of electrons lost equals the number of electrons gained.

As we can see, the number of electrons lost (8 e-) in the oxidation half-reaction is larger than the number of electrons gained (2 e-) in the reduction half-reaction. To equalize these, multiply the reduction half-reaction by 4 and the oxidation half-reaction by 2:

2 MnO4- (aq) + 8 H2O → 2 Mn2+ (aq) + 16 e-
4 HNO2 (aq) + 12 H2O → 4 NO3- (aq) + 8 e-

Now the total number of electrons lost in the oxidation half-reaction equals the number gained in the reduction half-reaction.

Step 6: Combine the two half-reactions, canceling out the electrons.

2 MnO4- (aq) + 8 H2O + 4 HNO2 (aq) + 12 H2O → 2 Mn2+ (aq) + 16 e- + 4 NO3- (aq) + 8 e-

Cancel out the electrons:

2 MnO4- (aq) + 8 H2O + 4 HNO2 (aq) + 12 H2O → 2 Mn2+ (aq) + 4 NO3- (aq)

Step 7: Simplify and verify the coefficients.

After simplifying:
MnO4- (aq) + 4 H+ + 3 HNO2 (aq) + 3 H2O → Mn2+ (aq) + 3 NO3- (aq) + 2 H2O

From the balanced equation, we can see that the coefficient for H+ is 4.

User Icon for Explain Bot Explain Bot answered
11 months ago

To balance the given redox reaction, follow these steps:

Step 1: Identify the elements that undergo oxidation and reduction. In this case, we can see that manganese (Mn) is reduced from +7 oxidation state in MnO4- to +2 oxidation state in Mn2+, and nitrogen (N) is oxidized from +3 oxidation state in HNO2 to +5 oxidation state in NO3-.

Step 2: Write down the unbalanced skeleton equation:

MnO4-(aq) + HNO2(aq) ---> Mn2+(aq) + NO3-(aq)

Step 3: Balance the atoms other than hydrogen (H) and oxygen (O). Start by balancing the manganate ion (MnO4-). Since the only manganese atom involved in the reaction is in MnO4-, it should be balanced first. To balance the Mn atoms, add a coefficient of 1 in front of Mn2+ on the right side:

MnO4-(aq) + HNO2(aq) ---> 1 Mn2+(aq) + NO3-(aq)

Step 4: Balance the oxygen atoms (O). There are 4 oxygen atoms in MnO4- and 3 oxygen atoms in NO3-. To balance them, add a coefficient of 3 in front of NO3- on the right side:

MnO4-(aq) + HNO2(aq) ---> 1 Mn2+(aq) + 3 NO3-(aq)

Step 5: Balance the hydrogen atoms (H). There are 1 hydrogen atom in HNO2. To balance it, you need to add a coefficient in front of H+ on the left side. Let's call this coefficient x:

MnO4-(aq) + x HNO2(aq) ---> 1 Mn2+(aq) + 3 NO3-(aq) + x H+(aq)

Step 6: Balance the charge. Looking at the overall charge, we can see MnO4- has a charge of -1 and Mn2+ has a charge of +2. To balance the charges, add two more electrons (2e-) on the left side, as the electrons are gained during the reduction reaction:

MnO4-(aq) + x HNO2(aq) + 2e- ---> 1 Mn2+(aq) + 3 NO3-(aq) + x H+(aq)

Step 7: Finally, balance the nitrogen atom (N). There is one nitrogen atom in HNO2 and three nitrogen atoms in NO3-. To balance them, add a coefficient of 3 in front of HNO2 on the left side:

MnO4-(aq) + 3 HNO2(aq) + 2e- ---> 1 Mn2+(aq) + 3 NO3-(aq) + 3 H+(aq)

So, the balanced equation with the smallest whole number coefficients is:

MnO4-(aq) + 3 HNO2(aq) + 2e- ---> 1 Mn2+(aq) + 3 NO3-(aq) + 3 H+(aq)

From this balanced equation, we can see that the coefficient for H+ is 3. Therefore, the correct answer is option 1: 3.