Does this cartoon give accurate description of ph?

[boxfishpooalot]

What do you think?

[Randy Holmes-Farley]

The scale goes slightly beyond 0 and 14, but other than that, it is basically correct.

[boxfishpooalot]

So if theese guys keep adding bags of acid and base(in equal portions), what happens to water? Lets say they never stop adding it. Does the alkalinity raise up but stay at ph 7?

[Randy Holmes-Farley]

It gets very hot and salty, but nothing else happens if they are adding equal molar amounts of HCl (hydrochloric acid/muriatic acid) and NaOH (sodium hydroxide; lye).

There is no alkalinity remaining when they neutralize each other.

[boxfishpooalot]

Hmm I find that interesting, and a good dipiction of ph. If the ph on the picture was lets say seawater chemistry (8.3 with 2.3alk) and they kept adding acids and buffers(in equal portions) the ph and the alkalinity of the water would stay the same?

Edidted
So unless you add an acid or a buffer thats greater than a base or acid the ph will not change?(please dont include Co2 in this evaluation)

[Randy Holmes-Farley]

Acids and bases in equal proportions will change only the salinity, not the alkalinity.

HCl + NaOH ---> Na+ + Cl- + H2O

[boxfishpooalot]

So the ph stays the same at all ph levels, but gets saltyier. And the alkalinity changes only when one compound is added in excess of greater value (acid is more than base) Would make a more acidic ph/lower the ph.

[Habib]

I have got a feeling that Randy might feel sorry that he said: it is basically correct.




IMO, the cartoon only shows that pH 7 is neutral and above 7 it is basic and below 7 it is acidic.

[boxfishpooalot]

Originally posted by Habib
I have got a feeling that Randy might feel sorry that he said: it is basically correct.




IMO, the cartoon only shows that pH 7 is neutral and above 7 it is basic and below 7 it is acidic.

So if its basic theres all kinds of different "buffers" that make it that ph(like bicarbonate,carbonate ect). So acids and bases are just nothing but salts(or minerals?) that give you a ph. This is
cool

Ps-sorry if I keep rambling on, and on. But Im really understanding alot from this and the difference in ph and alkalinity.

[Randy Holmes-Farley]

Strictly speaking, true buffers are always a combination of two or more compounds, one of which can take up protons at the pH of interest, and one of which can loose them.

So bicarbonate + carbonate is a buffer because HCO3- can loose one and CO3-- can take one up in the pH rang eof about 7.5 to 9 (in seawater).

When you react a strong acid and strong base, the product is a salt and water.

[boxfishpooalot]

Last one
If we got a ph of 8.2 and alkalinity is 2.3(a mix of lets say bicarbonate and carbonate) to lower the ph you gotta add an acid. If I am right then I understand the difference in ph and alkalinity

[Randy Holmes-Farley]

If we got a ph of 8.2 and alkalinity is 2.3(a mix of lets say bicarbonate and carbonate) to lower the ph you gotta add an acid.

In that circumstance, you can lower the pH by adding CO2 (carbonic acid) which will lower the pH but not the alkalinity, or you can add a mineral acid (like HCl) which will lower both the pH and the alkalinity.

Likewise, you can raise the pH by removing CO2 from the system (which has no effect on alkalinity), or adding a base like sodium hydroxide (which will raise alkalinity and pH)

[boxfishpooalot]

Well I think I got a handle on ph and alkalinity thanks Randy!

[Randy Holmes-Farley]

You're welcome.

Happy Reefing.

[zenzence]

I think the real question is where did you get the cartoon?

[Boomer]

In Habib's new pH manual not yet published and in review

[Du]

ROFL, great thread

[Hobster]

Originally posted by Boomer
In Habib's new pH manual not yet published and in review

Is he the one on the left??

[Boomer]

Yes, good guess , as he has a very acidic personality

[Habib]

No neither one is me.

Judging from the construction of the balance, it is not a logarithmic response. So it defintely is not me.

[boxfishpooalot]

You guys crack me up!

[Boomer]

Yes Hab that is ture for sure, as you are a -log reponse