All Questions
Tagged with everyday-chemistry experimental-chemistry
93 questions
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Actives ph adjustments doubts
I hope someone can answer my question please.
Should I measure the pH value after each addition of active ingredients in my cosmetic formula to ensure that the active ingredient remains within its ...
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0
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0
answers
30
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Calculation of concentration for standard curve
for my enzyme fluorescent assay measurements in soil samples I have to calculate my standard curves. In a protocol, I have found this table where I cannot comprehend the reasoning how the author has ...
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2
votes
1
answer
146
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Why is the Molar mass of CO2 different than the weight of the sum of its particles?
The Molar mass of CO2 is stated to be 44.009 grams per mol
But in a calculation of the weight of each atom's particles((Electrons,Protons,Neutrons) times Avogadro's constant
I get 44.36 grams per mol
...
- 155
0
votes
1
answer
89
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About whitish layer that formed on chocolate bar
I noticed a whitish layer on the surface of a chocolate bar that I ate yesterday. I looked at the pack where it was mentioned that,
"Temperature and humidity changes may cause product to develop ...
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1
answer
152
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betamechaptoethanol smell [closed]
I am doing my masters in science and today one of our neighbors from the other lab came to heat his samples on a heating pad. the samples were in small tubes which contained Betamechaptoethanol, when ...
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2
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0
answers
30
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How are gravimetric analyses of particulate matter performed, in order to determine particulate matter concentration in air?
I've been surfing Google Scholar a bit and learned that a common and comparatively less expensive method of measuring particulate matter concentration in air was analysis through gravimetric methods. ...
- 121
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1
answer
210
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Is there any chemical that can react with two different chemicals to generate heat or cold? [closed]
For example. There are three chemicals. Chemical A,B,C
Chemical B react with Chemical A = heat
Chemical B react with Chemical C = cold
Is there any chemical available like this? And is it safe to ...
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0
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1
answer
454
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Chemistry behind adding methyl salicylate to iodine dissolved in petroleum jelly [closed]
We did a project at my school where we were asked to create a pain-relieving balm, inspired by Iodex. We first took 50gms of petroleum jelly and heated it in a water bath until it melted and became a ...
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0
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3
answers
6k
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What is mAh/g Specific capacity?
In battery chemistry I've been reading about specific capacities of various electrochemical cells as $\pu{mAh/g}$. For example, in one article it says the specific capacity of the system is $\pu{75 ...
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0
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1
answer
484
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What is the best ratio of salt to water when using a salt solution in the electrolysis of water?
I am using the electrolysis of water to provide middle school students with a phenomena to explore chemical and physical change. The set up is producing much more hydrogen gas than oxygen gas and I am ...
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1
answer
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Fluorine detection in organic compounds
Many of you will know why I am asking this question. There is a lot of attention recently to the dangers of the so called Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS). In essence organic ...
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0
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53
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Best practices to obtain small quantity of sealed solution without oxidising entire solution?
I'm ordering liquid based chemicals which only come in large bulk quantities. These solutions have a shelf life of approximately 2 years unopened, but 2 - 3 weeks once opened and oxidation kicks in. ...
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1
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0
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43
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How to prepare an emulsion (compounds in wt%)
I am trying to replicate an experiment to generate microparticles but I found myself confused about how to prepare the ingredients as some need to be weighed and dissolved before and I think the ...
-4
votes
1
answer
107
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How Bread is made with yeast, sugar and luke warm milk? [closed]
Materials and Apparatus:
wheat flour
sugar
dry yeast
glass bowl
covering plate
milk
Procedure:
Lukewarm milk is taken in the glass bowl and sugar is added to it. Then, yeast is added to the same.
...
- 101
3
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0
answers
69
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Can color-changing leuco dyes be used to indicate when a certain molecule binds to another in a textile fabric?
Thermochromic leuco dyes change color when the temperature changes. I want to use leuco dyes to make a color-changing fabric. However, instead of using temperature to induce color changes, I want the ...
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2
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1
answer
70
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Diffusion of multiple gases at once
Graham’s law of diffusion states the rate of diffusion between two gases is inversely proportional to their molar masses. Now, this is helpful when we are focused on two gases. But that is rarely the ...
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1
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509
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How do I calculate weight percent of BaCl2
A $\pu{0.1036 g}$ sample containing only $\ce{BaCl2}$ and $\ce{NaCl}$ is dissolved in $\pu{50 mL}$ of distilled water. Titrating with $\pu{0.07916 M}$ $\ce{AgNO3}$ requires $\pu{19.46 mL}$ to reach ...
0
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0
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108
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Betaine HCl solution at neutral pH
I was trying to make a $2\text{M}$ solution at $\text{pH}\, 7.5$ of Betaine $\ce {HCl}$.
I started by weighing out the appropriate amount of Betaine $\ce {HCl}$, added some water and started stirring. ...
- 17
1
vote
0
answers
549
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Calcium chloride as a drying agent for solutions
I'm aware of the reaction Calcium chloride has with water vapour and how it can therefore be used as a good and inexpensive drying agent but could that be applicable for solutions?
For example if ...
- 748
0
votes
1
answer
31
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Hazard and precautionary statements
Is there a scientific database where one can find all the H and P statements for all chemicals? I would like to avoid using wikipedia but I can't find a database from a trusted source.
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6
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3
answers
937
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Does partially/completely removing solid shift the equilibrium?
For the reaction: $$\ce{P4(s) + 5O2(g) <=> P4O10(s)}$$
Let's say the reaction is at equilibrium, and SOME $\ce{P4O10(s)}$ is removed from the reaction. Will that affect equilibrium? My ...
user105067
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0
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83
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Why does dissolved oxygen concentration decrease with increasing atomic number of metals?
I am looking at how metal ions ($\ce{Fe^2+}$, $\ce{Ni^2+}$, $\ce{Cu^2+}$, $\ce{Zn^2+}$, and $\ce{Ag+}$) affect the biochemical oxygen demand in water and used the Winkler's method to find out the ...
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0
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356
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Stirring bar cleaning
I have a small question concerning the stirring bars cleaning. I use mine in BOD test wastewater for 5 days and I want to clean them so my question is can I soak them overnight with sodium ...
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2
answers
47k
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How to make foggy and cloudy plastic fully transparent?
I used sandpaper of different grits to sand the surface of plastic. The surface is smooth but it looks dull after sanding. I read that one could use toothpaste to remove the foggy look but it did not ...
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-2
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2
answers
626
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What is the essence of chemistry? [closed]
I am an engineering student who loves physics but didn't quite enjoy chemistry.
a. When I was in high school chemistry to me was something not as inspiring as physics but in which I couldn't solve ...
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1
vote
3
answers
88
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Need reactants for a rocket [closed]
I am doing a project in chemistry at the moment to build a rocket out of materials that can be easily bought and that react strongly to create thrust.
I was wondering if anyone knew a good chemical ...
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2
votes
1
answer
278
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Detecting impurities in polyethylene glycol 3350
I would like to test samples of polyethylene glycol 3350 ($\ce{H−(O−CH2−CH2)_n−OH}$ with an average molecular weight of 3350, so n is around 75) to determine if there are any impurities and if so the ...
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-2
votes
1
answer
224
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Can water be generated artificially [closed]
As we all know water that in many of the countries or states we find a lot of water scarcity. I wonder if water could be produced by artificial technology. I searched about this in google but I find ...
0
votes
1
answer
3k
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Calculating numbers of moles at equilibrium given the volume of mixture and initial concentration of reactants [closed]
The equilibrium between three substances, A, B and C Is shown below.
$$\ce{A(g) + B(g) <=> C(g)}$$
Initially there were $\pu{0.1 mol}$ of A and $\pu{0.2 mol}$ of B in the reaction mixture. A and ...
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1
answer
72
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Why doesn’t it burn? [closed]
In this video by Chatzida - 11 Fascinating Chemistry Experiments (Compilation) there’s an experiment where they light a bank note on fire, but it doesn’t burn. Why doesn’t it burn?
7
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2
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2k
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Why does ethylamine have two infra-red spectra? Are both correct?
The one I have in my textbook is this:
Shouldn't the first trough at $3500$ to around $3000$ mean that it's an $\ce{O—H}$ group with a $\ce{C—H}$? And then the other trough at $1700$ be a $\ce{C=O}$? ...
- 107
0
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1
answer
91
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Formation of Calcite from Calcium carbonate
So, in lab we are forming the different polymorphs of calcium carbonate. It required us to age the sample that was prepared for the formation of calcite for one week. This sample mixture was suspended ...
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1
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266
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if we mix bleaching powder in water will this be converted to Sodium Hypochlorite? [closed]
if we mix bleaching powder in water will this be converted to Sodium Hypochlorite ?
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1
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2k
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Is bleaching powder same as Sodium Hypochlorite? [closed]
i want to know is Sodium Hypochlorite is same as bleaching powder.
can some one please let me know.
- 119
2
votes
1
answer
840
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Significance of shapes of Conical flask and Kjeldahl flask
What is the practical significance of the shapes of conical flask and Kjeldahl flask?
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1
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401
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How does one determine whether a chemical requires hazardous waste disposal?
It is pretty easy to find information about the actual hazards of a chemical in the SDS, but I have been struggling to sort out which classifications require that the compound be handled differently, ...
- 115
0
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1
answer
373
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Independant variable for Asprin pill titration with NaOH solution [closed]
I am assigned to do an independently designed chemistry experiment for school. I want to do titration of Aspirin pills with NaOH solution using Phenolphthalein as indicator. I am struggling to find ...
21
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5
answers
6k
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How would I measure the Carbon Dioxide content in Coca Cola over a period of time?
I'm sorry if this is a broad question, but I am trying to plan a simple experiment. I am wondering is there a somewhat simple way of continuously measuring $\ce{CO2}$. I already know the initial ...
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1
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0
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126
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Starch Amylase Experiment using Iodine
The starch and iodide test is to detect amylose, a polysaccharide. We add an iodide solution to a sample and observe a color change with the starch; it turns dark blue. I am doing a bio/chem ...
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1
answer
45
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What is the use of both mol and mass representing the same thing i.e. amount of something? [closed]
A mol is a unit but also has a magnitude. How can a unit have a magnitude? And if mole is used to measure an amount of substance than what does mass measure?
3
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1
answer
118
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Coffee Degassing
I roast coffee, and currently package it in plastic bags with one way 'degassing' valves.
As soon as coffee is roasted, it starts giving off $\ce{CO2},$ a process which continues for days, and ...
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5
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4
answers
938
views
accurate measurement from inaccurate tools [closed]
It is a very general question. Is there a good way to systematically increase the accuracy and precision of a measuring tool using only mathematical means? For example, average 10 measurements can ...
- 169
1
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0
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156
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How to remove the foggy discoloration in polycarbonate tubes caused by acetone?
Unknowing that the tubes used in the centrifuge are made of polycarbonate, I cleaned them with acetone. Following, a white smoky discolouration appeared and the tubes turned opaque. Is there any way ...
4
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1
answer
6k
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Producing soap from sodium carbonate and oil
Can we get soap by mixing $\ce{Na2CO3}$ from seaweeds with oil?
I am not good at chemistry and saw this in the anime Dr. Stone. I just want to know if it is true or not.
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5
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1
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848
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How can I figure out if my store bought chlorine is the percentage it says it is?
Chlorine is an important part of maintaining any pool. I've read horror stories of people buying chlorine from pool stores or big box stores and the chlorine being ineffective.
If stored long enough ...
8
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3
answers
2k
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How much salt (or any other substance one can find in a kitchen) do I need to add to make water boil at 104 °C?
I've seen some formulas around in other questions and Google searches, but my chemistry is pretty much dead so I have no clue where to find the relevant values to calculate it myself. I just need to ...
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16
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1
answer
3k
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Using a gas stove instead of Bunsen burner for a flame test?
In all chemistry labs we use the Bunsen burner. What's the difference between it and a good old gas stove used in home? Can the stove also be used to get positive flame tests for some cations (like $\...
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0
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1
answer
3k
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When a solution is diluted, the number of moles of the solute decreases. what would happen to the molarity? [closed]
When a solution is diluted, the number of moles of the solute decreases, so the molarity decreases??
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6
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2
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2k
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Scientific Reason for Salt Solution Gaining Volume
A little background to this question: my mom placed a glass with salt and enough water to just cover the salt in a room to "absorb negative energy" out of the room at her office. It obviously "worked"....
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2
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1
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953
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Applications of magnesium sulfate monohydrate MgSO4 · H2O
How is magnesium sulfate monohydrate $\ce{MgSO4 * H2O}$ used for in chemistry and how does it work as a valuable laboratory drying agent?
I could not find too much information in my book or the ...
