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.

learn more… | top users | synonyms

0
votes
0answers
15 views

Difference between Excess property and property changes of mixing

I have some confusion in my mind about the difference between an excess property and a property change of mixing. I know that the Excess property is defined as the difference between the actual value ...
3
votes
2answers
96 views

Separating Lipids from Milk

I am trying to develop a procedure to test the percent mass of lipids in (update: homogenized) milk. It doesn't need to be very accurate, just an interesting application of chemical principles. As I ...
1
vote
1answer
34 views

Most efficient way to purify household vinegar: distillation or freezing?

I am aware that there are better ways to purify acetic acid out of a water-acid mixture than these, but which one out of distillation (using heat) and fractional freezing (using cold) would gain a ...
0
votes
0answers
13 views

Compute pressure vs temperature phase diagram of mixture

I would like to compute the phase diagram of a mixture of say 30% glycol and 70% water. I've found many diagrams of temperature vs ratio at constant pressure, but none with pressure vs temperature at ...
3
votes
1answer
138 views

Strictly speaking, is air homogeneous?

Why would air be considered homogeneous in its gaseous state (by Wikipedia and several other sources) even though its concentration keeps varying with time? A homogeneous fluid as i think of it is as ...
3
votes
2answers
37 views

Why did a former emulsion of oil and water precipitate after heating and cooling when heat made it originally?

I added 100 g coconut oil, 100 g distilled water and 500 mg lecithin to an 1800 watt blender. The motor from the blender has has a passive heating action. I blended it at full for four minutes. The ...
0
votes
1answer
71 views

Reaction of iron with steam

While studying about reversible reactions, my professor stated that the following reaction is a reversible reaction: $$\ce{Fe + H2O <=> Fe3O4 + H2}$$ She also stated that the product ...
1
vote
1answer
41 views

Volume changes when mixing DMSO and water

Since I know that a mixture of 500ml $\ce{H_2O}$ and 500ml ethanol gives less than a liter of mixture I wonder how strong this effect is when mixing DMSO and $\ce{H_2O}$. I'd assume it's nonzero - but ...
0
votes
0answers
27 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
37 views

Interactions between water and oil

I haven't thought about the forces that attracts oil to water (it is weak). The attractions between water molecules are caused by hydrogen bonds (primly), while oil through London forces. But between ...
1
vote
0answers
16 views

Highest ratio of ethanol to propylene glycol in a solution to still have minimal evaporation under ambient conditions? [closed]

How much ethanol can be added to propylene glycol before significant evaporation would start?
12
votes
2answers
235 views

Why does the ink on my whiteboard move?

...or at least I thought so, when I saw that the ink that was on my whiteboard last night became really messed up the next day. The image below shows my whiteboard before (on the left) and after (on ...
0
votes
0answers
28 views

How to calculate pH of strong base and weak acid flows in a reactor?

I have a bubble column and I would like to calculate the pH that follows, when I have two fluids with different volumetric flow rates coming into the reactor (one is a weak acid an the other is NaOH). ...
0
votes
0answers
21 views

What are good things to mix iron filings with to pour into a mould?

A project that I'm working on requires me to construct a shape like a cube with a spherical cavity inside it and further requires that the shape be ferromagnetic. I have on hand a PLA mould for making ...
0
votes
0answers
38 views

Preparation of stock chemical powders and efficient way to mix/blend and store them

Somebody possibly can tell that i'm in someway duplicate that post, but let me continue. Here is a recipe for a culture media for plants and all amounts are in mg/L. Boric Acid 10 Cobalt ...
0
votes
1answer
62 views

Does ethylene glycol sink in water?

I’m a little concerned that there is a far stronger mix of antifreeze in my car's coolant system than I am aware. I check the antifreeze level in my car (using a refractometer) when the engine is cold ...
4
votes
1answer
73 views

What is the molecular interpretation of Raoult's law?

I was reading about Raoult's law which states: It states that the partial vapour pressure of each component of an ideal mixture of liquids is equal to the vapour pressure of the pure component ...
0
votes
0answers
17 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' ...
0
votes
0answers
38 views

Mixture ; 70% isopropyl alcohol / distilled 5% acidity white vinegar

Use for homemade cleaning solution, I have an equal parts 5% distilled white vinegar, along, 70% isopropyl alcohol. Lying concerns are of any possible transfer / relocation of the prepared mixture, ...
1
vote
0answers
48 views

Mixture of boron, barium, and yttrium [closed]

I am doing research for a book and would like to find out what the outcome is when boron, barium, and yttrium are mixed together?
3
votes
1answer
935 views

What is the solvent and what is the solute?

This question is and I am learning about mixtures, solutions, solutes, solvents, and other terms related to these words. I know that a solute is the substance being mixed with or dissolved into the ...
1
vote
2answers
57 views

Is water a heterogeneous molecule? [closed]

My question is based upon the statement found here: an element may be homogeneous on a larger scale, compared to being heterogeneous on a smaller scale. This is known as an effective medium ...
3
votes
1answer
81 views

Does adsorption occur between liquids?

While reading a paper in a field other than chemistry, the author mentions a phenomena that he labelled "adsorption" and describes it as follows: ...I am told (though I do not know which liquids ...
0
votes
0answers
20 views

Solution to reduce surface tension

What is the best and simplest solution to reduce surface tension? Normally you would use soap for this, but im search of something that has the same effect as soap but does not include all the other ...
1
vote
0answers
23 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
19 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 ...
3
votes
0answers
40 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 ...
0
votes
1answer
67 views

Fractional Distillation

Why does the long length of the fractionating column in fractional distillation enable more effective separation of two liquids in a mixture? (basically what's the purpose of the fractionating ...
5
votes
1answer
662 views

Why does tea dissolve better when put in water rather than milk?

I sometimes drink tea with or without milk. What I have noticed is that when I dip the bag in water the tea spreads out evenly and I have a cup of tea in like 5 minutes. But when I do the same with ...
2
votes
2answers
176 views

What does all chromatography have in common?

We're learning about chromatography in class, and I'm confused about all the different types (e.g. those that separate liquid-liquid solutions vs. those that separate liquid-solid solutions vs. those ...
1
vote
0answers
28 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 ...
2
votes
1answer
24 views

How to refer to this method of mixing solids?

The steps of this process are: Fill a container with water (or other solvent) Add mixants (is that the right word?) the container Stir until all mixants are dissolved/suspended Boil off the water ...
4
votes
1answer
174 views

Total pressure in a chamber calculation

I have a chamber containing two different gases and a liquid which needs to be heated at a certain temperature to bring it to vapor state. I have worked out that we can calculate the total pressure ...
0
votes
1answer
133 views

What does my textbook mean by saying this about petroleum?

"Petroleum consists of crude oil and natural gas and contains a mixture of up to 300 hydrocarbons, including sulfur and nitrogen compounds. It is formed over thousands of years from the remains of ...
1
vote
1answer
60 views

Doubt about effusion/diffusion

Suppose a a container contains a gaseous mixture of methane and hydrogen. The mixture effuses out through a hole in the container. Now hydrogen is lighter gas so it must effuse faster and all of ...
1
vote
0answers
50 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 ...
6
votes
2answers
134 views

Miscibility of Molten Metals

While reading about the size of atoms and ions of the Group 1 elements in the textbook "Concise Inorganic Chemistry" by JD Lee, I came across this line: The Li+ is much smaller than the other ...
3
votes
1answer
122 views

Freeze distillation: Does efficiency depend on solubility?

I was surprised to learn that freeze distillation has the same inefficiencies as vapor distillation: Namely, that it is impossible to get two miscible fluids to fully separate in one "pass" of ...
5
votes
0answers
91 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 ...
2
votes
1answer
21 views

Get the molar mass of a polymer in a mixture given its osmotic pressure

Have a dissolution with $12$g of an unknown polymer for each liter of solution at $25^\text{o}$C has an osmotic pressure of $12.1$ torr. What is the molar mass of the polymer? Apparently the formula ...
1
vote
2answers
65 views

Get the molar fraction of a mixture component given only its pressure

You have a mixture of $\ce{He, Ne, Ar}$ gases with a total pressure of $8.40$ atmospheres. $\ce{He}$ has a pressure of $1.50$ and $\ce{Ne}$ has $2.00$. What is the molar fraction of $\ce{Ar}$? ...
2
votes
1answer
91 views

Find number grams of the solute in a dissolution given its density and Molarity

Have a dissolution of $\ce{HNO_3}$ in water. The density is $1.42\ce{g/mL}$ with a concentration of $\ce{16M}$. What is the concentration in % mass/mass? Alright. So the % mass/mass is ...
3
votes
1answer
3k views

Heat capacity of mixtures

After reading this recent question I was interested in how to calculate the specific heat capacity of a mixture based on the specific heat capacities of its components. According to this website the ...
5
votes
0answers
178 views

Water/ethanol mixing problem

In the following question, the water/wine mixing problem was recast in chemical terms. However, partial molar volumes can make this a much more challenging problem than it appears on the surface. ...
9
votes
3answers
5k views

Are all homogeneous mixtures just solutions?

Or can there be a homogeneous mixture that is not a solution?
6
votes
2answers
505 views

Reactions between enantiomers in a racemic mixture

As a follow up to this question I started thinking about another question. During racemization, enantiomers are mixed in a equal ratios to form an optically inactive mixture. What type of reactions ...
1
vote
2answers
98 views

homogeneous mixture - Are they truly uniform in composition and proportion?

If 5ml alcohol is dissolved in 1 L of water ( the purpose is to highlight the low quantity of one of the liquids) , how is it possible for 5 ml to evenly dissolve in 1 L of water ? There is not enough ...
2
votes
1answer
670 views

Mixing solvents and other compounds - safety issues

I would like to know if it is safe to mix organic solvents together or organic solvents with some compounds listed below. In a mixture with random ratios (greater than zero - all chemicals present) ...
2
votes
1answer
179 views

What is the CO2 content in the air in a compartment of air and water, as a function of temperature?

Update 31.12.2015: In a closed system of water and air, how does the concentration of CO2 change as a function of temperature, in the gas phase? What is the graph of carbon dioxide ($\ce{CO2}$) ...
5
votes
0answers
43 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 ...