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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.

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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 ...
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Anyone ever heard of phosgene? [closed]

Some helpful background before chemistry related questions. I cleaned my floors with spray nine disinfectant cleaner (active ingredient is dimethyl benzyl ammonium chloride). It wasn’t rinsing well ...
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0answers
15 views

Relation between enthalpy of vaporization and Gibbs Energy [duplicate]

I came across with this formula and I don’t understand why is it true, maybe one can help me to understand it and how to obtain it. $$ \frac{\Delta H_{vap}}{T^2} = \frac{\delta(\frac{\delta G}{T})}{\...
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2answers
45 views

How do I calculate the total volume when i mix 1000 kg of glucose with 5000 L of water

I want to know how to calculate the resulting volume when I mix 1000 kg of glucose into 5000 L of water. How does the calculation change if I'm mixing NaCl into the water, instead of glucose? Or ...
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0answers
39 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 ...
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3answers
3k views

Is it possible to boil a liquid by just mixing many immiscible liquids together?

In open air, when vapour pressure reaches 1 atm, boiling takes place. I read that if we add two immiscible liquids together, the total vapour pressure of the 'mixture' is close to $p = p^*_A + p^*_b$,...
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1answer
60 views

Miscibility of Hexane and Ethanol (Anhydrous vs 96%)

In my lab, I mixed 8:2 (mass:mass) of Hexane:Ethanol (Hexane: 0 ppm of water content, ...
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2answers
31 views

Average Molar Weight

We have a mixture of two gases, say nitrogen and hydrogen. To calculate the average molar weight M , the formula says: M (average) = (hydrogen pressure/100).M(H2) + ( 1 - nitrogen pressure/100).M(N2)...
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Can a stoichiometric mixture of oxygen and methane exist as a liquid at standard pressure and some (low) temperature?

This answer to the question Pre-mixing cryogenic fuels and using only one fuel tank written by a non-chemist (me) begins with: At STP: LOX's boiling point is 90.19 K Methane's freezing ...
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1answer
27 views

Why do properties of colloidal solution depend only on dispersion medium's physical state? [closed]

According to a past year JEE question, properties of colloidal solution depends only on dispersion medium's physical state and not on nature of dispersed phase or dispersion medium, or temperature of ...
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1answer
35 views

Mass fraction in a mixture of metal salts given the total mass of the metal

I am trying to solve a question in my study and I don't get the answer required. A mixture of $\ce{NaNO3}$ and $\ce{Na2SO4}$ weight $5.37$ grams, the $\ce{Na}$ = $1.61$ grams. What is the ...
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47 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 ...
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3answers
166 views

Why does Coca-Cola Zero Sugar Contain Sodium Despite no Sodium Ingredients?

According to the Coca-Cola website and every label I read, Coca-Cola Zero Sugar is a mixture of organic compounds: CARBONATED WATER (OC(OH)₂), CARAMEL COLOR (Various sugars), PHOSPHORIC ACID (H₃PO₄...
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0answers
18 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 $20^{\circ}C$). ...
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1answer
26 views

How do I identify how many reactions are occurring when precipitating a mixture?

An example of a question is: After dissolving $x$ grams of a mixture of $\ce{Na2SO4}$ and $\ce{NaCl}$ in water, you add an excess of $\ce{BaCl2}$ solution. You filter off the precipitate which ...
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2answers
62 views

Wetting agent for H2O2 solution

I need to increase the wetting of an $\ce{H2O2}$ solution on ceramic surfaces. Does anyone know of a common chemical I can use for this? The properties it would ideally have are: Increases wetting ...
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2answers
92 views

How to separate two liquids with both having the same properties?

I was curious if it was possible to separate such liquids e.g. two vegetable oils that happened to have different ingredients, so it is a different liquid, but the same density etc.
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1answer
31 views

Mix quaternary ammonium compounds with washing powder [closed]

So to get rid of bad smells from clothes that have stayed wet for long, I am wondering if I can just add a disinfecting product to my wash in addition to regular washing powder. I have a product ...
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0answers
196 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 ...
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1answer
129 views

Connection between Gibbs Energy of Formation and Gibbs Energy of Mixing

Recently I found the following formula, which I cannot verify to be correct. Since I found this formula in several publications I assume that it is correct but I don't know why. First there is the ...
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1answer
69 views

Is the stoichiometric coefficient equivalent to the mole fraction?

I have a small problem to understand (or distinguish between) two concepts of free mixing enthalpy. In several textbooks, I found the following formula for the molar free mixing enthalpy (binary ...
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2answers
65 views

Is the %V/V composition defined for homogeneous mixtures? [duplicate]

Why do major websites such as NASA and Wikipedia discuss the composition of the earth's atmosphere in terms of percentage by volume instead of percentage by amount of substance? Isn't the percentage ...
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1answer
265 views

What forms the emulsion in chocolate?

Some days ago, before buying a chocolate I read the ingredients and saw that it contains a natural emulsifier. A Google search didn't reveal anything about of what the emulsion formed is, do you have ...
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1answer
42 views

How to evenly mix NaCl and Lactose

Q: You have 10 g NaCl (s) and 90 g Lactose (s) (both easily soluble in water.) You want to achieve a 100 g mixture of these two compounds in solid form where they are completely evenly mixed. (A 1 mg ...
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1answer
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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 ...
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284 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....
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1answer
124 views

Separating sugar from soda

I want to do a lab with my students in which they will try to prove how much sugar is in a can of coke. I know that distillation is the go-to method for separating out the syrupy sugar mix, but does ...
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1answer
137 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 ...
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0answers
65 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 ...
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1answer
88 views

How do antioxidants work? [closed]

A friend and I are doing a project that involves the process behind manufacturing Jet A-1 and specifically the specifications highlighted in DEF 91-91. I was interested to see the information at the ...
3
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0answers
391 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 ...
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1answer
41 views

Which is the suitable process for ball milling?

Why do we mainly choose the wet ball milling process in spite of dry ball milling process? Both processes are used to make a homogeneous mixture of different compounds.
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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 ...
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1answer
364 views

How to separate paracetamol and caffeine?

How do you separate paracetamol and caffeine using high-school laboratory equipment? I was thinking about using the fact that paracetamol has a lower melting point (169 °C) compared to caffeine (...
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1answer
70 views

Derivation of formula used in calculating molecular mass from a mixture

In a solution to a problem, to calculate Molecular mass of unknown gas from a mixture containing $\ce{O2}$ in $80~\%$, the author used the formula : $\frac{1}{\sqrt{M_\text{mix}}}=\frac{X_{\ce{O2}}}...
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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 ...
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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 ...
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1answer
7k views

How to calculate the vapour density of a mixture?

I have a gaseous mixture of $\ce{H2}$ and $\ce{CO2}$ which contains $66\%$ by mass of $\ce{CO2}$. I have to figure out the vapour density of the mixture (defined as mass of a certain volume of a ...
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1answer
255 views

How to calculate the latent heat when there is a boiling temperature range?

I have a DME (dimethyl ether)- methanol - water mixture with the mol fraction composition: DME 0.4295, methanol 0.1353, water 0.4351. This mixture has a boiling temperature range: dew point 141.6 °C ...
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1answer
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Heating a mixture of methanol and water?

I have a mixture methanol and water, at 25°C, and I want to take it to 250°C. I'll use two heat exchangers: one for taking the mixture from a liquid state (25°C) to a vapor state (X°C), and the second ...
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1answer
733 views

Will water allow salts to be dissolved in methanol (that are otherwise poorly soluble)?

If we make a mixture of water, methanol and a salt like $\ce{FeCl2}$, $\ce{NaCl}$ etc, will the ability of water and methanol to mix allow $\ce{FeCl2}$ and $\ce{NaCl}$ to be a part of this mixture and ...
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1answer
967 views

Is it possible for a compound to be soluble in a mixture of solvents but not the individual solvents?

Some weeks ago one of my friend needed to use turpentine. As a good but ignorant chemist on that point I did some research about it. I found (at the beginning) in the French wikipedia page of ...
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2answers
241 views

Mixing water and oil in microgravity outside of a container

What would happen if I where to mix water and oil in a vacuum in microgravity where the temperatures were low enough so that the oil and water remain liquids also, the mixture is not inside of a ...
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0answers
330 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 ...
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3answers
517 views

How does a mixture not retain its chemical identity?

My book says that matter can be classified as an element, compound, or mixture. It further says that a pure substance (or substance) is matter that has distinct properties and a composition that doesn'...
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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 ...
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1answer
2k views

Will adding apple cider vinegar to freshly pressed fruit juice preserve it

Would adding apple cider vinegar to freshly cold pressed fruit juice be able to preserve the fruit juice and extend its shelf life? Would the juice change into vinegar with time?
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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 ...
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1answer
114 views

Is it possible for the remaining solute of a saturated solution to form a single even phase from top to bottom (similar to that of a colloid)?

If a solute that dissolves in a liquid solvent has reached high enough levels to cause saturation within the solution, is it possible for the remaining solute particles to form an evenly distributed ...
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1answer
54 views

Is there a way to find the mixture type with just the molecular formulas and masses of the solute and solvent?

If you had the molecular formula and molar mass of a solvent and a solute and no other specific information about the two, could one deduce the type of mixture (suspension, colloid, solution) they ...