Unanswered Questions
241 questions with no upvoted or accepted answers
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Mass of boron in boric acid
I have recently submitted a slime activator product for EN71-3 UK toy safety testing. The test aims to measure the amount of boron that is able to migrate from the toy if it is consumed by a child in ...
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Non-binding buffer at pKa of roughly 6 that dissolves in ethanol?
I'm trying to find a proper buffer for my experiment, which I'd appreciate some suggestions on. I have a solution in which I want to measure the concentration of magnesium ions using a fluorescent ...
- 38.4k
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Calculating the pKA value of a mixture of two weak acids?
Will it be possible to find the pKa value of two weak acids? I am working on a project for school on calculating buffer capacities and to find the pH of the buffer solution, I have seen that you need ...
- 1,126
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Experiment on pH vs Rate of Electrolysis - what do the results actually say?
My experimental setup looks at using different pH solutions (of $\ce{H2SO4}$ and $\ce{NaOH}$) for electrolysis of water with a Hoffman setup and then measuring the rate of production of gas (note this ...
CommunityBot
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How to dissolve a powdered drug once it has been mixed with water
For a biological experiment I have acquired $\pu{10 mg}$ of CHIR 99021 (laduviglusib). In order to obtain a $\pu{10 mM}$ stock solution, I had to dissolve the powder in $\pu{2.15 mL}$ of dimethyl ...
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Salts solubility and speciation calculations using PHREEQC
I am collecting data from literature for CO2 solubility in aqueous solutions. These are usually synthetic brines and are reported as molalities or wt% of salts or salt mixtures (I have NaCl, KCl, ...
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Assessing stability of protein used for interaction experiments after changing buffer from tris to HEPES
I have a protein with a theoretical $\mathrm{pI}~9.0$ currently stored in $\pu{25 mM}$ tris and $\pu{250 mM}$ $\ce{NaCl}$ $(\mathrm{pH}~8)$ at $\pu{−80 °C}.$ I need to do experiments in HEPES at $\...
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Who is more polar: acetonitrile or methanol?
According to data dipole moment of acetonitrile is around 4 while that of methanol is 1.7 but is said that acetonitrile is more soluble in non polar solvent that methanol.
But shouldn't methanol be ...
- 36
2
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Stability of n-Dodecyl-beta-D-maltoside in buffer solutions for assay experiments
I have a buffer system which contains multiple salts and in addition DTT and n-Dodecyl-beta-D-maltoside.
I understand that DTT is hydrolysing quite fast and this component must be used always fresh ...
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Estimation methods for temperature evolution of a high $\Delta H_{mix}$ dilution ($\ce{KOH}$ in water)
Question up front: Can temperature evolution in solutions be short-hand-estimated by simple state based calculations - with reasonable expectations of precision? (+/- 10° C)
I am trying to calculate ...
- 2,805
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What does it mean for a substance to be "sparingly soluble"?
I have trouble understanding what solubility means. Merriam-Webster defines it as follows:
1 the quality or state of being soluble
2 the amount of a substance that will dissolve in a given amount of ...
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Increasing energy density for flow batteries with water based electrolyte?
Given a flow battery with a water based electrolyte, would it be possible to increase the energy density of battery by precipitating the redox active species from the anolyte and catholyte solutions? ...
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Freezing of a beverage
I am trying to generally describe the process of freezing beer and how the different ingredients influence the freezing process. My general approach right now is to observe a beer as 90% water and 10% ...
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3
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Why are buffer solutions not neutral
I am very confused about buffer solutions and I have lots of ideas about them which don’t integrate together so I really can’t tell which are correct and which are wrong. That being the case it’s ...
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Mass of gaseous ammonia required to prepare ammonia solution of a given pH
How many grams of gaseous ammonia do you need to make $\pu{200 mL}$ aqueous ammonia solution with $\mathrm{pH} = 11.34?$
As the mole ratio is the same for $\ce{H+}$ and $\ce{NH3},$
$$\ce{NH3 + H+ -&...
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