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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: Jaya C on February 19, 2015, 12:32:28 PM

Title: How to prepare a dilute Hcl
Post by: Jaya C on February 19, 2015, 12:32:28 PM

Dear Members :

I am a newbie to this forum.

I work as a high school teacher in bangalore. I have following query

1) What is the ratio that i need to follow for preparing the diluted Hcl from concentrated Hcl
2) How to prepare dilute H2SO4 (Sulfuric Acid) from concentrated H2SO4

Appreciate your help. Thanks

Title: Re: How to prepare a dilute Hcl
Post by: Dan on February 19, 2015, 12:56:54 PM

http://www.wikihow.com/Dilute-an-Acid

Title: Re: How to prepare a dilute Hcl
Post by: Arkcon on February 19, 2015, 12:58:08 PM

Quote from: Jaya C on February 19, 2015, 12:32:28 PM

I have following query

1) What is the ratio that i need to follow for preparing the diluted Hcl from concentrated Hcl
2) How to prepare dilute H2SO4 (Sulfuric Acid) from concentrated H2SO4

We like to help, but you have to ask more complete questions.  Perhaps we're facing a language  barrier, but science should allow us to work past that, in someway.  We have to know what concentration you have, and what concentration you want, numerically.  The words concentrated and dilute aren't specific enough.

Now, in times past, there were standard definitions of what those words meant that everyone accepted.  But that may not be the case for modern methods.  I know you're working as a high school teacher, so maybe the archaic definitions could be used, but they really shouldn't

Try to review the entire procedure, and post what's relevant, if you still need help after review.

Title: Re: How to prepare a dilute Hcl
Post by: UKInstrumentation on March 09, 2015, 07:36:28 AM

I just quickly looked at this and wanted to add - never add water to acid - add the acid to water.

The sulphuric acid will generate heat - so when you add to water be very careful.

Title: Re: How to prepare a dilute Hcl
Post by: curiouscat on March 09, 2015, 08:06:58 AM

Quote from: UKInstrumentation on March 09, 2015, 07:36:28 AM

I just quickly looked at this and wanted to add - never add water to acid - add the acid to water.

The sulphuric acid will generate heat - so when you add to water be very careful.

A related question came to my mind. Say you had to neutralize acid instead of diluting it. e.g. H2SO4 with NaOH.

Is the recommended procedure adding acid to base or the other way around or does it not matter much?

Title: Re: How to prepare a dilute Hcl
Post by: billnotgatez on March 09, 2015, 10:30:44 AM

Intuitively, and not from any accurate knowledge.
Add more concentrated to less concentrated.
Add stronger to weaker.

This is just to get the discussion going since I never remember it discussed in school.

Title: Re: How to prepare a dilute Hcl
Post by: Arkcon on March 09, 2015, 07:37:05 PM

Quote from: curiouscat on March 09, 2015, 08:06:58 AM

A related question came to my mind. Say you had to neutralize acid instead of diluting it. e.g. H2SO4 with NaOH.

Is the recommended procedure adding acid to base or the other way around or does it not matter much?

The real issue is with sulfuric acid, not that I would dilute conc. nitric nor conc. hydrochloric acids.  Its just that sulfuric acid generates much more heat, and so much dense than water, a few drops of water would skitter about on the sulfuric acid surface, and sulfuric acid's viscosity would make it function like a cup, practically guaranteeing a splash.

If you wanted to neutralize a liter of conc. sulfuric acid with a strong solution of NaOH in water, you should probably pour the acid into the NaOH.  If I had to neutralize 20 gallons of strong, contaminated sulfuric acid, contained in a  gallon steel drum, and I was using soda ash, or other technical grade dry caustic, maybe I would slowly dump it in, if there wasn't an engineering solution available to drop some in automatically.