Questions tagged [osmosis]
the spontaneous net movement of solvent molecules through a semi-permeable membrane into a region of higher solute concentration, in the direction that tends to equalize the solute concentrations on the two sides.
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Relation between dilution and osmotic pressure
The following question is taken from IAT 2024, an entrance test for research institutes in India at the high school level:
Which one of the following plots correctly describes the variation of ...
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Is there a way to calculate the osmotic pressure between two or even three solutions?
From what I've read about osmotic pressure, the "measurement" and "calculation" of osmotic pressure always applies to a system in which "pure water" and a solution is ...
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Does osmotic pressure depend on the quantities of the outer membrane solvent?
$$\pi V = nRT$$
What is the osmotic pressure at $\pu{25^oC}$ of an aqueous solution of 0.0010 M $\ce{C12H22O11}$ (sucrose)?
We just need to substitute the data into equation (13.4)
$$\pi = \frac{\pu{...
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What is the exact definition of isotonic solutions?
Background of the Question
I am a high school student so maybe my understanding of this topic is quite less, so apologies in case I have asked an elementary question.
My chemistry sir taught that :-
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Can you clearly explain what osmotic pressure is?
There are two main questions I'm struggling to get my head around.
What exerts osmotic pressure? Is it the molecules of the solvent (water) or solute particles (sugar) ?
Where is it exerted? On the ...
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When does osmosis stop?
In the figure given below:-
Since only solvent particles can move through semipermeable membrane, if we manage to keep pressure on both the containers equal say by keeping weights, will osmosis go ...
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Difference in salinity and/or sugar content: Does it have a name? [closed]
Let's say that I put a tea infuser full of high-salt and/or high-sugar content, into a tea pot full of fresh water. I know that the salt and/or sugar will move from the infuser to the tea pot until ...
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What is the osmosis equilibrium point of water beads (for plants)?
In theory, water beads for plants take in water when immersed in it to gradually release it to the roots of the plants. This process happens through osmosis. When the relative humidity is high enough, ...
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What is the significance of semipermeable membrane in osmosis? [closed]
My teacher said that semipermeable membrane allows passage of only selected particles and then said that it is required for osmosis but I cannot totally understand the main function of semipermeable ...
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Passing protons through cation-permeable membranes
Protons are attached to a water molecule (making hydronium) in acidic solutions. If a container was split through the middle with a cation-permeable but anion impermeable membrane and, say, HCl was ...
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What happens to a solute's potential energy during diffusion?
I was thinking, if you have a large amount of water, with an uneven solute concentration, diffusion will lead to an even concentration of solute throughout the solution.
Intuitively,that would mean ...
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How do concentrations of different solutes across a cell membrane affect whether water leaves or enters the cell?
I know from class that water travels to where the solute concentration is higher. I have no problem visualizing it if it's just "salt." What if there are multiple types of solutes? For ...
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Osmotic pressure for non-electrical neutral region of a solution
For calculation of the osmotic pressure, we can use Van't Hoff equation as below:
π=CRT
If we put the solution in an electrical field, the cations and anions move towards negative and positive pols, ...
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Will osmosis still occur if there is no water on the other side of the semi-permeable membrane?
During the following experiment: Take two peeled potato-halves and
scoop each one out to make potato cups. Put each potato cup in a
trough containing water. Now,
Keep Potato-cup A Empty
Put one ...
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What is the maximum osmotic pressure that can be exerted with water as the solvent at room temperature?
Lets say we have a membrane which separates a tank of pure water from a tank of water saturated with a solute(there are also undissolved chunks of solute which can immediately dissolve if water is ...
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Recovery of Urea from aqueous solution [closed]
When adding Urea to water, the reaction is highly endothermic. I was playing with the idea of using that for a Desktop cooling system, but for that, I'd of course have to recover that Urea from the ...
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Do solids in a solution also apply partial pressure? If yes, can this be used as an intuitive explanation for osmosis?
I know that in a mixture of different gases, we can assign every type of gas molecules a partial pressure so that the total pressure is the sum of all partial pressures. This can be extended to gas ...
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Why one compartment in an osmotic container have different pressure?
I am reading about osmotic pressure and the derivation in Wikipedia, states:
Consider the system at the point when it has reached equilibrium. The condition for this is that the chemical potential of ...
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Understanding the Osmotic Pressure formula
$$\Pi = iMRT$$
Can this be rewritten as $\Pi = ORT$ where $O =$ osmolarity? The only reason I ask is because my book doesn’t talk about the relationship between osmolarity and molarity, but I came ...
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Finding freezing temperature and osmotic pressure of an ethylene glycol and glycerol solution in water
A water solution is prepared by mixing $\pu{200 g}$ of a ethylene glycol (ethan-1,2-diol; $\ce{C2H6O2}$) solution (20% by weight) with $\pu{500 g}$ of glycerol (propan-1,2,3-triol; $\ce{C3H8O3}$) ...
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What is the relation of water potential with gibbs free energy? [closed]
In my high school textbook, they have stated that diffusion is a process in which water moves along a free energy gradient. I cannot understand how water potential may be related to the Gibbs free ...
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How does hydraulic equilibrium work on the particulate level?
I recently learned that osmosis occurs when there is a semipermeable membrane between pure water and a solution of water. The pure water then fills up the solution's side until, as my textbook put it,
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real meaning of osmotic and turgor pressures
I am a high school student and I am very confused in how we define osmotic pressure? Osmotic pressure is defined as the pressure required to stop the diffusion of solvent into a solution by applying ...
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What is the difference in mosM and mOsm units, if there is any at all?
I'm reading Agre's paper on aquaporins [1] and he uses a unit called "mosM" throughout the paper, for example:
… ocytes were transferred from 200 mosM to 70 mosM modified Barth's buffer.
I ...
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Why does osmolarity take into account both penetrating and non-penetrating solutes?
According to Wikipedia:
… osmolarity takes into account the total concentration of penetrating solutes and non-penetrating solutes, whereas tonicity takes into account the total concentration of non-...
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Why is RO water more corrosive?
According to several articles from the American Water Works Association, permeate from RO should be stabilized in terms of pH and hardness to avoid corrosion of the distribution piping.
How does ...
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Questions Regarding Osmosis
From Costanzo's Physiology:
Osmosis of water is not diffusion of water: Osmosis occurs because of a pressure difference, whereas diffusion occurs because of a concentration (or activity) difference ...
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How is equilibrium achieved in osmosis?
According to BRS Physiology book:
excessive NaCl intake will lead to an increase in the osmolarity of the Extracellular Fluid (ECF) compartment, and thus will lead to water shift from the ...
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Is reverse osmosis a fancy term for filtration?
In Reverse Osmosis (RO) systems, the water to be purified is pushed against a semipermeable membrane and comes cleaner the other side, the path of water is the reverse of regular osmosis, hence the ...
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Is the salt of a weak acid and a weak base also a weak electrolyte?
I'm able to find a lot of information on acids and bases, as well as strong-strong, weak-strong, and strong-weak salts. However all the introductory materials on electrolytes just stop there and say "...
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Using osmotic pressure to find the molar mass of a compound
Working on-board a research vessel somewhere at sea, you have (carefully) isolated 12.5 micrograms $(\pu{12.5E-6 g})$ of what you hope is pure saxitoxin (a non-electrolyte) from a poisonous (and quite ...
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membrane for a reverse osmosis desalination experiment
We are second year cram schoolers , we are currently working on a project tackling water desalination by reverse osmosis and are required to do an experience. During the process, we encountered some ...
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Is the solution isotonic, hypertonic, or hypotonic?
The problem is shown below. I don't understand how can the tonicity of a solution be determined if the solution has multiple solutes dissolved in it.
Do I take the total sum of the mass of solutes ...
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How to find osmolarity of a solution contatining salt and glucose?
What is the osmolarity of a solution that contains $4.00\%$ (m/v) $\ce{NaCl}$ $(M = \pu{58.44 g mol-1})$ and $3.00\%$ (m/v) glucose $(M = \pu{180.18 g mol-1})?$
I know you have to convert percentages ...
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Breast milk with reverse osmosis [closed]
I would like to make life lasting breast milk jewelry. I would need at least 5ml to make it. I've been doing a lot of research to get the best results, so far this questions are the result of more ...
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What are the factors affecting osmosis (bio)? [closed]
Asking from the blood barrier angle. The wikipedia states that glucose, urea, and $\ce{Na/K}$ count. Can there be any other factors, like $\mathrm{pH}$, temperature, hydraulic pressure on the cell ...
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Is osmosis really a special case of diffusion across a semipermeable membrane?
A general idea we have about osmosis is that it is the movement of solvent particles through a semi permeable membrane from a region of high concentration to a region of low concentration. This seems ...
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Is it appropriate to approximate solute particles in a dilute solution as an ideal gas?
I was studying osmosis and I came across the formula for osmotic pressure. I decided to see the derivation for osmotic pressure in a dilute solution. The derivation involved an equation involving the ...
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Is Gibbs energy change during osmosis positive? If so then why is it spontaneous?
For ideal solution, μA=μA* +RT
lnxA
ln function is an increasing function, means that the higher the xA the higher the μA......(1)
Now consider osmosis. From Atkins' Physical Chemistry Ninth ...
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Dependence of Osmotic Effects on Particle Size
van't Hof's equation for osmotic pressure is derived with the assumption, among others, that the particle size of the solute is comparable to the particles size of the solvent. It holds well so long ...
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Will a reverse osmosis membrane exclude perfluorobutanoic acid?
I recently did a water quality test and it showed a detectable level of perfluorobutanoic acid, a potentially dangerous carboxylate PFC.
Will a reverse osmosis water purification system exclude this ...
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Mechanism of Water Potential
The idea of water potential still confuses me. I understand the general idea: water moves from an area of higher water potential to an area of lower water potential. However, I still do not understand ...
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Why does water diffuse from a lower solute concentration to a higher one?
I'm studying biology and this came up in the context of passive transport. I understand why, in general a gas moves down a concentration gradient (the random movement of gas particles and probability)....
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Molar mass of a protein from osmotic pressure
The height of a column of liquid that can be supported by a given pressure is inversely proportional to its density. An aqueous solution
of $0.010 g$ of a protein in $10 mL$ of water at $20^oC$ ...
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What does the osmotic pressure do in an electrolytic solution?
I have learnt that in an electrochemical cell, the osmotic pressure in the solution hinders the flow of ions from the electrode to the solution, rather some ions may accumulate on the electrode ...
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Why does sugar water diffuse better than water through a gummy bear?
Our science class did a lab about osmosis, where we left a gummy bear in solutions of salt and sugar, as well as tap water. When we came back, we were all surprised to see that our gummy bears in ...
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Is Reverse Osmosis Sanitizer safe to use? [closed]
The Sanitizer is called Sani-System (For Reverse Osmosis). The purpose is to get rid of the bacteria within a Reverse Osmosis system (Priority is the tank: that holds the water)
-- edit
Safe meaning ...
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Is osmosis due to osmotic pressure?
Okay, I am getting real confused on how water flows from a hypotonic solution to a hypertonic solution through a semipermeable membrane. It is known that hypertonic solutions have higher osmotic ...
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Why does solvent particles move towards solution when semi permeable membrane is added?
When a SPM is added in between solute and solution the water molecules move towards salt water even though the concentration is same both sides. Why does this happen? According to SPM's perspective, ...
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Reverse osmosis membrane used as an osmosis membrane
I recently came across the so-called 'thin-film composite membranes'. They are build up of layers with one of them being semipermeable. As I'm not well versed in chemistry, I'm unsure, if these ...
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