Question #62a46

2 Answers
May 1, 2017

One way is to balance the equations by the oxidation number method.

Explanation:

Your first unbalanced equation is

KClO3KClO4+KCl

Step 1. Calculate the oxidation numbers of every atom:

+1K+5Cl-2O3+1K+7Cl-2O4++1K-1Cl

Step 2. Identify the atoms that change oxidation number.

The changes in oxidation number are:

Cl: +5 → +7; Change = +2
Cl: +5 → -1;llChange =m-6

Step 3. Equalize the changes in oxidation number.

You need 3 atoms of Cl that increase oxidation number for every 1 atom of Cl that decreases oxidation number. . This gives us total changes of +6 and -6.

Step 4. Insert coefficients to get these numbers.

KClO33KClO4+1KCl

Step 5. Balance K.

4KClO33KClO4+1KCl

Every substance now has a coefficient. The equation should be balanced

Step 6. Check that all atoms balance.

AtommLeft Hand SidemRight Hand Side
mKmmmmmm4mmmmmmml4
mClmmmmmll4mmmmmmml4
mOmmmmml12mmmmmmm12

The balanced equation is

4KClO33KClO4+KCl

Now, can you use the same technique to balance the second equation?

Here's a video that might help.

May 1, 2017

14KClO3+4I2+4HNO3+2H2O7KClO4+7KCl+8HIO3+4NO

Explanation:

I'm going to assume it is in an acidic solution.

The first step would be to separate the overall equation into two half reactions, but you've already done that. So next would be to balance everything except for the H and O.

2KClO3KClO4+KCl

I2+HNO32HIO3+NO+H2O

Then balance the oxygen by adding H2O.

2KClO3KClO4+KCl+2H2O

I2+HNO3+5H2O2HIO3+NO+H2O

Now balance the hydrogen by adding H+.

2KClO3+4H+KClO4+KCl+2H2O

I2+HNO3+5H2O2HIO3+NO+H2O+7H+

Add e- as needed to balance the charges on each side of the equation.

2KClO3+4H++4eKClO4+KCl+2H2O

I2+HNO3+5H2O2HIO3+NO+H2O+7H++7e

Finally, multiply each half-reaction by an integer so that when they are added, the e- will cancel out. Then add them and simplify.

7(2KClO3+4H++4eKClO4+KCl+2H2O)

+

4(I2+HNO3+5H2O2HIO3+NO+H2O+7H++7e)

=

14KClO3+28H++28e+4I2+4HNO3+20H2O7KClO4+7KCl+14H2O+8HIO3+4NO+4H2O+28H++28e

14KClO3+28H++28e+4I2+4HNO3+202H2O7KClO4+7KCl+14H2O+8HIO3+4NO+4H2O+28H++28e

14KClO3+4I2+4HNO3+2H2O7KClO4+7KCl+8HIO3+4NO