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# Questions tagged [ph]

pH (or the potential of hydrogen) is a scale used to measure how acidic or basic an aqueous solution is.

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### Preparation of Copper (II) Sulfate Pentahydrate Solution

how would you make a solution of Copper (II) Sulfate Pentahydrate to achieve 150, 200, 250 and 300 mgL−1 concentration of copper? I do not have the anhydrous version of the solute. Also, when I ...
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### Influence of pH on precipitate crystallite sizes?

It's normally assumed that a higher pH of solution would slow nucleation rates and hence lead to larger crystal formation. I've found literature that it is due to solid-liquid inter-facial tension. ...
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### Naming convention for buffer solutions/systems

Is there an official naming convention to follow for buffer solutions/systems? I've noticed that the name of the buffer usually just follows the name of the salt (ex. sodium acetate buffer), but what ...
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### Formation of silica from TEOS

Usually tetraethyl orthosilicate/tetraethoxy silane (TEOS) is mixed with both ethanol and water to produce silica in a sol-gel process. I am curious what happens if one adds TEOS to water at a high pH,...
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### Reference Books on Electrolysis and Chemical Titration process [closed]

I'm in a General Chemistry course in college. We have laboratory, and then we are supposed to make a report on what we did, etc. I'm not entirely sure what the last laboratory was about, but it was ...
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### Calculate pH at equivalence point [closed]

Calculate the pH at the equivalence point of a titration of 62 mL of 0.1 M $\ce{CH_3NH_2}$ with 0.20 M HCl. The $\ce{K_b}=4.4\cdot10^{-4}$. At the equivalence point, the moles of CH3NH2 equals the ...
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### Can buffer solutions be used to control the pH of ethanol?

For my experiment, I want to investigate the effect of differing pH on the solubilities of a sparingly soluble drug. However, the solubility is too low for me to conduct a reliable study on the ...
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### Is it possible to determine the pH that results in maximum buffer capacity from a Bjerrum plot?

If buffer capacity is normally at a maximum when pH=pKa because there is an equal concentration of acid and conjugate base in the buffer (so there's an equal amount of substance that can absorb acid ...
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### Buffer Capacity Calculation

I know buffer capacity is the following: $$β=\frac{Δ(\ce{H+})}{Δ(\mathrm{pH})}$$ specifically the amount of acid/base that needs to be added to change pH by 1 unit. If I have data about how pH of a ...
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### Calculating Buffer Capacity

I completed a titration of Ammonium Acetate buffer solution and to it I added $\pu{2M}$ Hydrochloric Acid. I measured the initial $\ce{pH}$ of the buffer solution before any acid was added and I ...
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### Why does buffer capacity of tartrate buffer generally decrease as the buffer pH increases?

From what I see, the buffer capacity of tartrate buffer is generally decreasing as buffer pH increases. Why is this? Also, does this mean that tartrate buffer doesn't have a maximum buffer capacity at ...
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### Should the tip of the burette of an automatic titrator be immersed in the analyte?

In all the tutorials I found online, the tip of the burette (containing the titrant - NaOH) was immersed into the analyte solution. My question is: shouldn't the tip be out of the solution? Isn't ...
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### What are the concentration changes when diluting an equimolar acetic acid: acetate buffer?

When a buffer (for example, a mixture of 100 mM acetic acid and 100 mM acetate), is diluted 10-fold, all the concentrations change drastically. Surprisingly, after re-establishment of equilibrium, the ...
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I understand the concept of an equilibrium buffer solution, however I am a bit hung on how creating it doesn't shift the weak acid equilibrium. $$\ce{CH3COOH + H2O <=> CH3COO- + H3O+}$$ $$K_\... 3answers 8k views ### How do indicators work when they mixed with each other? Methyl orange, bromothymol blue and phenolphthalein indicators were mixed together to form a solution. Over what pH range would the solution be yellow? I cannot understand the question. If two or ... 3answers 551 views ### The effect of NaCl on the ability of an acid to protonate benzoate I've been doing several experiments using soda to quantify the amounts of caffeine and benzoate. Because of our methods of analysis, we had to decarbonate our soda. The experiment offered two ways for ... 1answer 1k views ### net charge nucleobases at alkaline conditions While doing anion exchange chromatography of a short oligonucleotide, I have noticed that at \rm pH=12, the oligo retains longer on the column than the same oligo- at \rm pH=8. I thought the ... 1answer 486 views ### What alkali and alkaline earth metal oxides will turn moist red litmus blue and finally white? [closed] How many of the following will turn moist red litmus blue and finally white? \ce{Li2O}, \ce{KO3}, \ce{RbO2}, \ce{Cs2O2}, \ce{BeO}, \ce{MgO}, \ce{BaO2}, \ce{SrO}. Since bleach ... 0answers 138 views ### What is the benefit of using a pH indicator reagent over pH strips or a meter? I've recently started getting into chemistry a bit as a hobby. Nothing serious, just amateur level stuff mostly, primarily just to educate myself. Whenever I need to determine the pH level of a ... 1answer 46 views ### Dissociation behaviour of polyelectrolytes Assuming a solution of 100 polycationic molecules, each of them carrying 100 amino groups and an apparent pKa of 6.5. Would it mean that, at a pH of 6.5, 50 molecules will be fully protonated 50 ... 2answers 134 views ### Can an acid have a high pH? [closed] I am studying anesthetics and came across thiopental which is considered a weak acid. However it has a pH of 10.5. I always learned that greater than 7 is alkaline. I’m looking for some guru to help ... 3answers 4k views ### How is seawater alkaline? If when water and carbon dioxide react they form carbonic acid, carbonate, and bicarbonate, how does seawater still have a pH of around 8? Doesn't a compound need an hydroxide ion to be a base? 1answer 69 views ### Concentration of Hydrogen Ions I am slightly confused about one certain task. There are 4 different solutions (\ce{NH3}, \ce{HCl}, \ce{NaOH}, \ce{CH3COOH}), their concentration is the same (c = \pu{1 mol L-1}). Which ... 3answers 68 views ### Solubility and pH I was reading about antacids. It stated that in earlier times \ce{NaHCO3} and a mixture of aluminium and magnesium hydroxide were used as antacids. In excess \ce{NaHCO3} can make the medium ... 1answer 2k views ### Acidic and alkaline salt solutions: why do some salt form acid/bases while others don't I have a question regarding salts and their solutions. How come some salts, like sodium carbonate and ammonium chloride, produce acids/bases when dissolved in water? Moreover, how can you predict ... 2answers 250 views ### Calculating dissociation degree from pH and Ka without given initial acid concentration Is it possible to calculate the dissociation degree (DD) from pH and Ka without directly been given the initial acid concentration? I found the following formula:$$\text{DD} = \frac{K_\mathrm{a}}{...
I am attempting to complete a question in which I need to use an ICE table to calculate the pH of a $\pu{2.61 mol L-1}$ $\ce{NH4HSO4}$ (ammonium hydrogen sulfate) solution. When $\ce{NH4HSO4}$ ...