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14 votes
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What is "gold number"?

A red gold sol is a colloidal suspension of gold nanoparticles with average size of particles less than 100 nm. The suspension is quite stable — the nanoparticles don't aggregate because of the ...
vapid's user avatar
  • 2,088
9 votes

Reaction of Iron(III) with hydroxide ion

I wouldn't expect the reactions to yield different products but rather different particle size. The higher concentrated $\ce{NaOH}$ should hereby produce smaller particles†. The "solution" in the ...
aventurin's user avatar
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8 votes

Weirdness From Boiling Gold Colloid Dry

Your original hypothesis is right. The remaining citrate salt decomposed and charred. Note that citrate ion is also oxidized while reducing Au(IV) to elemental gold. So your solution does not contain ...
AChem's user avatar
  • 41k
7 votes

Hardy Schulze law

In order to explain the Schuze-Hardy rule, you have to take into account that you are working with a colloidal dispersions stabilized electrostatically. The stability of this dispersions is well ...
PAEP's user avatar
  • 1,067
7 votes
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Colour of colloids

This is classic, the effect is called Mie scattering. Very simply speaking, light is scattered on the whole surface of every (translucent) particle. For round particles, interference makes a ...
Karl's user avatar
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7 votes
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Name of particles in a suspension

“Solid particles” is arguably the better term on its own, especially when size distribution is provided alongside with it. Alternatively, there is “dispersed phase” and its synonym “discontinuous ...
andselisk's user avatar
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5 votes
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Why don't particles of a colloid settle?

Particles in colloid absorb either positive or negative ion preferentially from solution depending on there surface. This develops a potential on colloid surface called ...
Abhik Bose's user avatar
5 votes
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Movement of solid particles in colloids

The short answer to this question is: yes. The movement of particles in suspension like the powder in water would be a perfect example of Brownian motion as Mithoron already said. The particles are ...
basseur's user avatar
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5 votes
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Bond-order parameter $g_6(r)$

Assume we are given a configuration of atoms $\{{\bf r_i}\}$ and any other data required to characterise the atomic layout, e.g. any lattice vectors if we have periodic boundary conditions in any of ...
Ian Bush's user avatar
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5 votes

Name of particles in a suspension

A colloidal suspension or a even a suspension consists of two phases: A dispersed phase and a dispersing medium. See this Table as an example: Table 3.3. Combinations of two phases in colloidal ...
AChem's user avatar
  • 41k
5 votes
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What kind of solution is formed when alkali metals are dissolved at high concentration in liquid ammonia?

Before asking what the nature of the solution is, let's fact-check the unsupported statements made: [OP] when the concentration of a solution of liquid ammonia is above 3 M, the alkali metal ions ...
Karsten's user avatar
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4 votes
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Can cationic species form micelles?

Cationic micelles similar to your examples can and do exist. For example cetyl trimethylammonium bromide (Growth of Cationic Micelles in the Presence of Organic Additives, P. A. Hassan and J. V. ...
airhuff's user avatar
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4 votes
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Why does the colour of gold sol change with particle size?

The color of conductive nanoparticles depends on plasmonics. In brief, quantum behavior predominates in the few electrons of a nanoparticle, rather than as a continuous conduction band. Surface ...
DrMoishe Pippik's user avatar
4 votes
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Does MgCl2 sol coagulate gold sol faster than Fe(OH)3 sol?

Option (c) is actually correct. Magnesium chloride does coagulate gold sol faster than ferric hydroxide, because ferric hydroxide does not coagulate in the first place. Wikipedia mentions that ferric ...
Pritt says Reinstate Monica's user avatar
4 votes

Are the particles of a colloid "solid"?

Colloidal solutions may contain particles made of liquids or of solids. The particles are liquid in substances like mayonnaise or moisturizer, whose particles are droplets of oil (in water) for ...
Maurice's user avatar
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3 votes
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Electric double layer formation

If you are confused about the electrical double layer, it is completely fine because electrochemists spent several decades to understand it and yet the concept remains "grey" in the minds of most ...
AChem's user avatar
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3 votes

Any example of colloidal solution where liquid Helium is solvent?

A solution implies that there are solvent-solute interactions. Helium is about the most chemically inert atom there is. In the case of water ice, the hydrogen bonding will be orders of magnitude ...
Li Zhi's user avatar
  • 31
3 votes
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Separating Lipids from Milk

Milk is mostly water, and diluting it (roughly speaking) with sulfuric acid to a concentration of ~50% milk and 50% sulfuric acid will result in a very acidic, but still aqueous, solution. We can ...
Curt F.'s user avatar
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3 votes

What is the molecular mechanism behind oncotic pressure?

The molecular basis of osmotic pressure (oncotic pressure is a special type of osmotic pressure) is similar to filtration but on a very small scale. Some membranes are partially permeable: they let ...
matt_black's user avatar
  • 36.8k
3 votes

How to prevent sedimentation of an EDTA suspension?

I see 4 possibilties to avoid EDTA sedimentation: Mechanical ways like shaking, mixing or container turning - but you say it is not applicable. Increasing viscosity by thickening glycerol to ...
Poutnik's user avatar
  • 42.2k
3 votes
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Why are nanoliposome encapsulated antibiotics still so unavailable despite being so effective?

Liposomes are the first nano-drug delivery systems that have been successfully translated into real-time clinical applications. So far, all liposomal drugs are designed for intravenous applications ...
Mathew Mahindaratne's user avatar
3 votes

Why are nanoliposome encapsulated antibiotics still so unavailable despite being so effective?

The FDA and other regulatory agencies require that formulations are subjected to a variety of tests. Clinical trials are laborious and expensive. Studies demonstrating efficacy in vitro, in small ...
Buck Thorn's user avatar
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3 votes
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Watercolor pigment conundrum - can a change in ionic profile induce flocculation?

What you state seems reasonable: salting-out can be used to precipitate some substances. If it were tempera paint, you could point out that proteins in egg albumin might precipitate, but I don't know ...
DrMoishe Pippik's user avatar
2 votes

How can proteins reduce surface tension?

I dont know why lactalbumin reduces the surface tension but If you know the concepts of surface tension and surfactants then it becomes easier to extrapolate on that concepts to reach the conclusion ...
Eka's user avatar
  • 2,768
2 votes

The entropy change during micellization

In order to accommodate the hydrophobic tail of the free surfactant, the hydrogen-bonded structure of bulk water must be distorted. A nonpolar hydrocarbon cannot form hydrogen bonds with water and ...
prc84's user avatar
  • 51
2 votes

Permanent cloudy colloid with water

Starch in water might work, perhaps with table salt or other bacterial/fungal growth inhibitor. Follow directions in most recipes: mix a bit of starch in cold water and then add gradually to hot water ...
DrMoishe Pippik's user avatar
2 votes

Any example of colloidal solution where liquid Helium is solvent?

This is a question to physics department. Chemists only see liquid helium when refilling NMR instruments. Boiling point and comfort working with changes in this order: ...
sixtytrees's user avatar
  • 2,000
2 votes

Formation of silica from TEOS

It depends. if your pH is really high, silicate $\ce{SiO3^2-}$ or $\ce{SiO4^4-}$ ions will form and will become a stable dissolved solute in the solution. if it is moderately high the rate of ...
A.K.'s user avatar
  • 12.6k
2 votes
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Generating colloids / nano-particles from palladium and platinum wire

A reliable method to obtain metallic nanoparticles in general is to reduce a metallic ion in presence of a capping agent. For a example, a traditional method to obtain gold nanoparticles (AuNPs) is to ...
KarlsMaranjs's user avatar
2 votes

What decides the nature of emulsifying agents?

An emulsifier is a surfactant. A surfactant is characterized by the fact that its molecule has one or more hydrophilic parts and one or more hydrophobic parts. The ratio between the molar mass of the ...
IV_'s user avatar
  • 271

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