# Tag Info

Accepted

### How to (numerically) model a phosphoric acid titration curve

Much easier is to calculate the inverse function $[\ce{Na+}]=f([\ce{H+}],K_\mathrm{a1},K_\mathrm{a2},K_\mathrm{a3})$. Calculate fractions of respective phosphate forms as the function of $\ce{[H+]}$ ...
• 42.1k

### Am I understanding buffering capacity against strong acid/base correctly?

Further to the answer by Poutnik the buffer capacity $\beta$ of a weak acid - conjugate base buffer is defined as the number of moles of strong acid or base $C_B$ needed to change the $p$H by $\pm1$ ...
• 30.6k
Accepted

### Why does "bis-tris propane" have two pKa values?

The compound "bis-tris-propane"(1,3-bis(tris(hydroxymethyl)methylamino)propane, also known as BTP) has 2 secondary amino groups and can be written as $$\ce{R-NH-R-NH-R}$$ which, both in ...
• 42.1k
Accepted

• 1,401

### Why does "bis-tris propane" have two pKa values?

Why, with symmetric functional groups, are there two equilibrium constants? If the functional groups are close together, there will be electrostatic interactions (coupling). Adding the first proton (...
• 40.6k

• 42.1k

### How to Prepare a Buffer Solution?

Here is what you would do in the lab (2 recipes, depending on your needs): You start by diluting the concentrated ammonia to about $\pu{100 m}\mathrm{\small M}$. Then, while measuring the pH, you add ...
• 40.6k
Accepted

### How to Prepare a Buffer Solution?

You have some of the chemistry wrong. Looking at your assumptions, concentrated ammonia is typically in aqueous solution, as is concentrated hydrochloric acid. You could have ethanol solutions ...
• 22.3k
Accepted

• 40.3k

### Calculating the pH of a 'buffer' solution?

Question: Determine the $\mathrm{pH}$ of the solution resulting when $\pu{100 cm^3}$ of $\pu{0.50 mol dm-3}$ $\ce{CH2ClCOOH}$ is mixed with $\pu{200 cm^3}$ of $\pu{0.10 mol dm-3}$ $\ce{NaOH}$. I'm ...
• 40.3k

### buffer "recipe" needed

A pH buffer at pH $6.2$ can be made in $4$ Liters water, by dissolving $\ce{104.8 g KH2PO4}$ plus $\ce{5.44 g NaOH}$. Adding $\ce{NaOH}$ will simply transform part of the dihydrogenophosphate ion into ...
• 28.6k
It is the molarity of total acetic acid/acetate content, so the 3rd option. It is quite general principle applied in the pH buffer context. You can have a wide rage of $\ce{pH}$ values with the ...