How Do You Balance Complex Redox Equations with Multiple Oxidation Changes?

[dajugganaut]

hi all, my chemistry assignment had a bunch of questions on redox equations balancing. i got stuck on this one:

[tex] \CrI_{3} + KOH + \Cl_{2} \rightarrow \K_{2}CrO_{4} + \KIO_{4} + KCl + \H_{2}O [\tex]

so far, i tried to find ON numbers of the various elements.
Cr changes from +3 to +6
I changes from -1 to +7
Cl changes from 0 to +1

this means that Cr and I undergo a loss of electrons, while Cl undergoes a gain. i don't know how to solve this question when there are multiple LEO.

can you help? =)

[ EDIT : my attempt at LATEX has proved to be yet another disaster ]

 

[stunner5000pt]

For your latex in the final tex it should be a FORWARD SLASH, not a backslash... thus the mess. Also you don't need a backslash to start off a new word. ANyway it look like this:

$$CrI_{3} + KOH + Cl_{2} \rightarrow K_{2}CrO_{4} + KIO_{4} + KCl + H_{2}O$$

i suggest you break into half cells as follows
$$CrI_{3} \rightarrow K_{2}CrO_{4} + KIO_{4}$$
$$KOH \rightarrow H_{2}O$$
$$Cl_{2} \rightarrow KCL$$

Balance everything exotic (like K, Cr, I, Cl) first. Then follow the usual steps for half cells. I know it doesn't look like it will work.. but if you balance each half cell properly in temrs of charge and atoms yu should be fine

 

[quicknote]

Hello! Balancing redox equations can be tricky, especially when there are multiple elements undergoing changes in oxidation numbers. Here are some steps you can follow to help you solve this equation:

1. Identify the elements that are undergoing changes in oxidation numbers. In this case, it is Cr, I, and Cl.

2. Write down the initial oxidation numbers for each element. In this case, Cr is +3, I is -1, and Cl is 0.

3. Determine the final oxidation numbers for each element. In this equation, Cr is +6, I is +7, and Cl is +1.

4. Find the difference between the initial and final oxidation numbers for each element. This difference represents the number of electrons gained or lost by each element.

5. Use this information to balance the equation. You can start by balancing the elements that undergo a change in oxidation number. In this case, Cr and I both gain 3 electrons while Cl gains 1 electron.

6. Once you have balanced the elements undergoing changes in oxidation numbers, you can balance the remaining elements. In this equation, you have 2 K atoms on the reactant side, but only 1 K atom on the product side. To balance this, you can add a coefficient of 2 in front of KCl on the product side.

7. Finally, check to make sure that the number of atoms of each element is balanced on both sides of the equation.

[tex] \CrI_{3} + 6KOH + 3\Cl_{2} \rightarrow 2\K_{2}CrO_{4} + 2\KIO_{4} + 2KCl + 3\H_{2}O [\tex]

I hope this helps! Remember to always pay attention to the changes in oxidation numbers and use them to balance the equation. Good luck with your assignment!