Questions tagged [experimental-chemistry]
This tag should be applied to questions relating to the theory, design, techniques or performance of chemical experiments. This includes but is not limited to theoretical structures, expected products, thermal calculations, and empirical analysis. Additional tags should be applied to narrow down the field of research.
1,891 questions
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Why not add iodine in the test tube while studying effects of temperature on starch amylase?
The procedure in the textbook is like below:
Heat the test tubes holding starch solution and amylase solution to the desired temperature.
Mix them.
Every minute transfer a drop of the mixture to a ...
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What is the evaluation order of sign and unit in chemistry quantities?
I am curious about the evaluation order when a chemistry quantity has both sign and unit, such as $+3.4\,\text{kJ}/\text{mol}$.
Because there is space between number and unit, I think $e = (+3.4) \, (...
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Testing Concentration of Ethyl Acetate in Fischer Esterification Through Acid-Base Titration
I am currently working on an IB Chemistry HL Internal Assessment and was considering investigating the equilibrium point of the following reaction in varying temperatures:
$$\ce{CH3CO2H + CH3CH2OH <...
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Condensation product at room temperature
In my laboratory manual, for preparation of dibenzalacetone via Claisen Schimdt reaction, it says that
i)Prepare a solution of 3.15 g sodium hydroxide in a mixture
of 25 mL ethanol and 30 mL ...
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Experimentally, which is more reliable, pKa values or molar mass found from a titration graph?
I am a first year undergraduate student who is in a second semester, level-100 chemistry course. I had a lab experiment where I had to find the concentrations of unknown analytes (i.e., HCl, CH3COOH, ...
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Why do we use mercury in a standard hydrogen electrode? [duplicate]
My textbook has a clearly marked mercury reservoir of sorts that connects the platinum plate to the copper wire but doesn’t mention anything about it. Why exactly mercury if you just want to complete ...
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Surfactant removal from carbon
I sonicated the graphite to reduce its particle size. At first sight, adding water alone did not achieve good dispersion. Therefore, a bit of Triton X-100 was added and graphite was completely ...
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Feasibility of low-power EPR
The EPR equation $h \nu = g_e \mu_B B_o$ appears to give a lot of flexibility in selection of magnetic field and frequency (Wikipedia on EPR) but in practice, fields/frequencies of around 0.3 T and ...
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Why does calorimetry often give lower enthalpy values than literature? [closed]
During a calorimetry experiment I noticed that the calorimetry measurements often gave enthalpy changes that are less exothermic than the values in literature. I am aware that the literature values ...
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Feasibility of extracting odor-related compounds from heated watermelon and tomato without GC–MS or a rotary evaporator [duplicate]
I am a high school student working on a research project about odor formation from heated fruits, especially watermelon and tomato.
Based on previous discussions and literature, it seems that heating ...
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Calculating osmotic pressure
I'm looking forward to computing the osmotic pressure of a system, using 1-pentanol as the draw solute in this experiment and water as the solvent. 1-pentanol is partially soluble in water making a ...
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Gaseous reactants which give Solid products
I was recently wondering of gases which react to give solid products. The classic example is that of ammonia and hydrogen chloride to produce white fumes of ammonium chloride, a standard test for the ...
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Quantifying thermal degradation of carotenoids in watermelon by UV–Vis and feasibility of extracting natural aroma compounds
Research context (summary):
I am conducting a small-scale experimental study aimed at developing a simple, laboratory-accessible method for producing natural aroma extracts from watermelon. The ...
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How to determine bulk composition of basic magnesium carbonate (xMgCO₃·yMg(OH)₂·zH₂O) using bulk techniques?
I am working with basic magnesium carbonate, the bulk composition of which can be written as: $\ce{xMgCO3. yMg(OH)2. zH2O}$
My goal is to quantitatively determine $x,y,z$ for a bulk sample.
Available ...
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Persistent decrease of deposition current on reused gold RDE
I have been repeatedly using a single gold 2-mm rotating disk electrode (RDE) tip to deposit a platinum metal and then measure the electrochemically active surface area (ECASA) and oxygen reduction ...
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