How do I go about setting this problem up..?

Clorox bleach is 5.25% sodium hypochlorite. The instructions say to add 1 cup of Clorox to 4 cups of water. Find the percent of sodium hypochlorite in the mixture.

Question

How do I go about setting this problem up..?

Clorox bleach is 5.25% sodium hypochlorite. The instructions say to add 1 cup of Clorox to 4 cups of water. Find the percent of sodium hypochlorite in the mixture.

anonymous · Answer

I better check on this before trying to help :)  These can be confusing...

mr._scampy · Answer

Alrighty, thank you.

anonymous · Answer

I think it's like this... adding to the pure water obviously dilutes the solution, right?

So before diluting, you have enough sodium hypochlorite to make the 1 cup solution have 5.25% strength.

Let's write that as a ratio of the chemical to the water...

5.25% / 1 cup   = 0.0525 / 1 cup

After adding 4 cups of water, we have the same amount of chemical but 5 cups of water.

new strength = 0.0525 / 5 cups

Then you probably want to change it back to a percentage.

mr._scampy · Answer

Okay, right. Thank you very much.

anonymous · Answer

glad to help!