Questions tagged [mixtures]
Questions related to the physical combination of two or more substances on which the identities are retained and are mixed in the form of solutions, suspensions, and colloids.
40
questions with no upvoted or accepted answers
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529 views
Dry water using graphite
Dry water or "powdered water" is essentially a bunch of extremely small water droplets surrounded by $\ce{SiO2}$.
Some time ago, I was messing around and mixed some powdered graphite with water. (The ...
6
votes
0answers
317 views
Density of non-ideal vapor mixtures
I'm looking for a reasonably accurate density of a mixture of two gases that act quite unlike ideal gases (generally steam and water-miscible solvents). We can get a first order estimate by taking a ...
5
votes
0answers
119 views
Raoult's law: is the molar fraction the molar fraction in the entire system?
I have two physical chemistry textbooks, one by Atkins and one by Levine, which seem to differ in their notation used when describing Raoult's law.
Atkins talks about the molar fraction term in ...
3
votes
0answers
112 views
Why do certain mixtures foam and others don't? How to predict if a mixture will yield a foam?
I recently acquainted myself with the skill of whipping a mixture of sugar, fresh brewed/ hydrated instant coffee into a pale, fluffy, stiff and stable foam. This, as some might know, is known as Café ...
3
votes
0answers
635 views
Calculating total volume mixing NaCl and water
I'm (as a non chemist) trying to calculate the the volume of a NaCl solution. The problem is that I know the volume of water prior to mixing in NaCl, but I want to know the volume of the solution ...
3
votes
0answers
97 views
How could I find the solubility of hydrocarbons such as iso- and n-Butane in liquid Methane?
I am trying to figure out the dissolution capacity of iso and normal butane in methane at very low temperatures (110K). This would allow me to make compositions that prevent freeze out of these ...
2
votes
0answers
51 views
What kind of chemical reaction happens when combining Tahini and Date syrup?
While both Tahini and Date syrup are quite thin, when mixed together they form a paste-like substance that is very delicious, and quite thick. But what kind of chemical reaction leads to such sudden ...
2
votes
0answers
360 views
Ethanol Water mixture viscosity
It is found that increasing composition of $Ethanol$ in $Ethanol$-$water$ mixture increases the viscosity of the mixture upto certain composition, but after that the viscosity begins to decrease again....
2
votes
0answers
146 views
Why does only a single azeotropic composition exist for a mixture of two given substances?
In the image below, which represents a generic composition vs. temperature plot for a mixture, there is a single intersection point between the vapor and liquid curves. This is due to the fact that ...
2
votes
0answers
115 views
Heat capacity of mixtures is higher than their pure contituents?
I'm currently studying the effects of how changing mixed-refrigerant compositions effects their heat capacity. Surprisingly, my data suggests that some combinations of mixed-refrigerants have heat ...
2
votes
0answers
99 views
Chemical theory, formula(s) that predict final *volume* of a solution?
I asked this question a couple years back regarding the volume of a mixture being less than the volume of the original solute and solvent, but this question asks if there is theory and/or formulation ...
2
votes
0answers
101 views
Composition of carbon rods in alkaline batteries
The carbon rods in batteries look somewhat similar to graphite, but they do not leave a significant mark on paper. What form of carbon are they? Are they simply just graphite with a large amount of ...
1
vote
0answers
41 views
Calculating concentration of a powder in a liquid
I'm trying to determine how to calculate proper measurements for a 5% concentration of a vitamin C ester powder (ascorbyl palmitate) mixed in a 50/50 carrier oil mixture (jojoba oil/squalane oil) with ...
1
vote
0answers
28 views
Carbon Capture Absorption with Henry's Law
Assume the Henry’s coefficient for water at $\pu{20 °C}$ is $\pu{1.6E8 Pa}.$ What is the mole fraction of $\ce{CO2}$ that will be dissolved in water assuming that it is at equilibrium with a flue gas ...
1
vote
0answers
28 views
Gelifying hydrogen peroxide
What substances could be used to gelify 60% hydrogen peroxide? I imagine anything organic like agar would be broken down by the radicals. I tried looking up what dentists use and the only thing that ...
1
vote
0answers
37 views
Mixing ink with alcohol, MEG and water
First of all, I'm not a chemist and my knowledge in chemistry is not that extensive. However, I would like ask the following question: are there any chemical reasons that would explain that mixing a ...
1
vote
0answers
40 views
How do blue shifts in Raman spectra indicate a co-crystalline compound?
The short conference paper The Acetylene-Butane Co-Crystal: A Potentially Abundant Molecular Mineral on Titan (mentioned in EurekaAlert's 'Bathtub rings' around Titan's lakes might be made of alien ...
1
vote
0answers
91 views
Over time what happens to soluble liquids with different densities
I have a case with two liquids: Water and another chemical which is miscible in water.
The chemical has a density of 800 g/l so it's 20% less dense than water.
Initially the chemical was mixed with ...
1
vote
0answers
4k views
Isolation of codeine phosphate from Tylenol 2
So here is my question. This may be controversial for some, but I would like to tell you it is purely speculative and has no bearing on anything I would actually do.
If one has in their hands a ...
1
vote
0answers
367 views
What is the pH of a solution that results of a mixture of two others with known pH?
Solution A has a pH of 1, soultion B has a pH of 6. If I mix the same volume V of each solution into one, what will be the pH of the resulting solution?
I'm guessing here as no more information has ...
1
vote
0answers
51 views
What happens if I increase the amount of water on water based epoxies?
I am using a water based epoxy coating that is composed of a resin and a hardener. There is a specific amount of proportion to use to obtain the optimum cured coating. But I am trying to introduce ...
1
vote
0answers
134 views
Would combining essential oils and carrier oils be okay in terms of flash point?
With NO scientific, or chemical background, I am making my own beard oils. I found essential oil recipes online to mix with one or many carrier oils to make beard oil. I want to be original by going ...
1
vote
0answers
66 views
Jamming Theory or DLVO Theory for Oobleck
After doing some research I came across two theories that explain the shear thickening effect of Oobleck. The DLVO theory which involves the suspension of molecules via two opposing forces [...
1
vote
0answers
38 views
Can SLES get too old?
I've been using SLES to break surface tension in some water solutions. However after a year or so it seems like the ability to break surface tension seems to wear off in the solutions. So my question ...
1
vote
0answers
52 views
How high is the variance of the shore D hardness for a synthetical resin?
I realize that the variance of hardness depends on the homogenity of the polymer throughtout a specific sample, the polymer itself and on the measurement, but maybe there are typical values.
To be a ...
1
vote
0answers
38 views
Internal treatments of gas cylinders for toxic gas mixture
The values of toxic components like $\ce{H2S}$, $\ce{NO}$, $\ce{SO2}$, etc. [in ppm level] get decreased after a while due to adsorption phenomenon. Manufacturers design some internal treatments in ...
1
vote
0answers
359 views
Reading enthalpy of mixing graph
I'm struggling to interpret enthalpy of mixing data. Given this plot, from this paper, say I want to calculate the heat released from mixing 0.29 mol of 7.7% ethanol with 0.71 mol of 28.7% ethanol to ...
1
vote
1answer
202 views
Is matter really divided in two categories?
Page 1 of almost every Textbook start with the ordinary divison of matter in 2 categories: Substances and Mixtures.
Substances, or Pure Substances sometimes, are defined
as a form of matter that has ...
0
votes
0answers
13 views
Energy and impurities balance for adsorption with a fixed bed (with description)?
Do you have any suggestion where to look for a source of information about energy and impurities (component) balance for adsorption of mixture CO2/H2O in fixed bed?
I have looked into many articles /...
0
votes
0answers
22 views
Gas / Gas mixture dynamic viscosity temperature and pressure dependance
I’m trying to get an accurate interpretation of certain gases ($CO_2$, $N_2$, $NO$, etc.) dynamic viscosity [Pa.s] as a function of temperature and pressure (afterwards determine the dynamic viscosity ...
0
votes
0answers
33 views
What is the result of the combustion of the mixture?
I prepared a little experiment about solid rocket propulsion. I have used water ($H_{2}O$), potassium nitrate ($KNO_{3}$) and saccharose ($C_{12}H_{22}O_{11}$).
I made the mixture in a pan by cooking ...
0
votes
0answers
44 views
Why Does Adding Catalyst Slow Down My Reaction?
I currently did a lab where I was meant to identify factors that increase the rate of the reaction. I reacted Glucose with Potassium Permanganate and used Sulfuric Acid as a catalyst. But in my ...
0
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0answers
28 views
Combining two high-VP chemicals to get a low-VP mixture
I'd like to do a class experiment as a metaphor for human relationships. Two people each have a different chemical which evaporates quickly (at STP). There is one glass between them. If only one ...
0
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0answers
84 views
Will evaporation from two immiscible liquids blow up a balloon?
Consider the following setup:
Two immiscible liquids A and B are placed inside a balloon at a temperature where neither one of them boils. The inside of the balloon contains some argon, and the ...
0
votes
0answers
102 views
Ethyl Acetate and other Solvents in a mixture: miscibility and stability
I was wondering about a heterogeneous solvent mixture containing multiple alcohols such as IPA, Ethanol, methanol etc. Would EtOAc (Ethyl Acetate) play nice in these mixtures at low volumes such as 1 ...
0
votes
0answers
92 views
Is the negative excess volume of ethanol/water the cause of my math error?
I have a binary mixture, say ethanol at $90\%wt$ ethanol, $10\%wt$ water. According to Perry's Chemical Engineers' Handbook 9th Ed., that mixture has a density of $0.81797g/cc$ (at $20^{\circ}C$). ...
0
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0answers
621 views
Why are Colloids Heterogeneous?
I understand that the definition of a heterogeneous mixture is a mixture in which 2 or more phases are present, i.e. you can see the mixture is not uniform. I know a homogeneous mixture is a mixture ...
0
votes
0answers
492 views
Exothermic liquid-liquid mixing
Does anyone know of a good example of two liquids mixing very exothermically? As a reference, I'm thinking more like NaOH and water boiling when mixed at room temperature than ethanol and water are ...
0
votes
0answers
33 views
Meaning of “Diffusion Rate”
A friend is trying to understand a paper which discusses the diffusion of proteins through milk. Rather than listing a diffusivity (with units [Length]^2/[Time]), the paper lists the 'diffusion rate' ...
-2
votes
1answer
58 views
Pressure-Volume Formula Question
I have a chemistry homework problem that states the following:
$6.2$ L of $N_2$ at $0.74$ bar is mixed with a $15.2$ L sample of $O_2$ at $0.35$ bar. The gaseous mixture is placed in a container of ...
