Hi, how do I change 10% hydrochloric acid to 4%

How do I change from 20 percent to 4petcent hydrochloric acid, do I use distilled water

Should just be a straight dilution, and yes, definitely use distilled water, and always add acid to water (not the other way around) as the reaction is exothermic and can be excessive depending on the quantities and concentrations- think explosive boiling over all over your kitchen and all over you while you stand over it.

Acid into water- always.

wrote:

How do I change from 20 percent to 4petcent hydrochloric acid, do I use distilled water


 

Yes, use distilled water.

Your title says 10% but your text body says 20%, which is it?

You can use this calculator to do the math. Scroll down to the Dilution Calculator PPM PPB Percentage
endmemo.com/bio/dilution.php

- To make 4% from 20% 1000ml HCl - you would add 1000ml of HCl to 4000ml of distilled water.
- To make 4% from 10% 1000ml HCl - you would add 1000ml of HCl to 1500ml of distilled water.

There is also a very useful app on the Google Play Store called Lab Hacks, it has a bunch of useful features including dilution.

Here is a copy and paste of another way of calculating it:

To create a 4% solution of HCl from a higher strength, you must divide the strength of the solution you have by 4 to determine how much you need to dilute your HCl. 

1. Divide the strength of your solution by 4.
2. If you have 35% HCl, divide that by 4% and you have 8.75 parts.
3. 1 part has to be the 35% HCl and 7.75 parts is distilled water.
4. So if you have 100 ml of 35% HCl (1 part), then you will need 7.75 parts x 100 ml = 775 ml of distilled water.
5. Add the 100 ml of 35% HCl to 775 ml of distilled water and you will have 875 ml of 4% HCl.