1 mole of NaCl has more osmotic pressure than 0.1 moles of sugar dissolved in 1 litre of water. Can you explain this answer? ThoughtCo, Aug. 26, 2020, thoughtco.com/calculate-osmotic-pressure-example-609518. Which is more osmotic 1 mole or 1 litre of water? You can study other questions, MCQs, videos and tests for IIT JAM on EduRev and even discuss your questions like where C = the molal concentration of the solution and corrects for the volume occupied by the solute molecules. Plants can also evidence the power of osmotic pressure as they grow. Reverse osmosis removes salt from seawater to produce fresh water. Put the answer in atm but with no units. "How to Calculate Osmotic Pressure." Osmotic pressure of urea solution at 10 ^\circ C is 500 mm. The osmotic pressure of a decimolar solution of urea at 2 7 0 C is: Easy. 60) of 60 g. per litre has the same osmotic pressure as a solution of cane sugar (mol. 0.16 mole CH3OH / 0.750 L. (1) = i n V R T = i M R T. where. Weve got your back. Osmotic pressure of 0.01 M aqueous urea is 0.24 atm. iii. wt. In this article we will discuss about:- 1. is done on EduRev Study Group by IIT JAM Students. has been provided alongside types of One liter of an aqueous urea solution contains 6 g of urea. 1 V 1 = nRT 1 and 2 V 2 = nRT 2. We provide you year-long structured coaching classes for CBSE and ICSE Board & JEE and NEET entrance exam preparation at affordable tuition fees, with an exclusive session for clearing doubts, ensuring that neither you nor the topics remain unattended. How do I choose between my boyfriend and my best friend? Can you explain this answer? Comparing the water potential inside a cell to that of outside a cell, the direction of osmosis can be determined. (Round off to one decimal place)[Given: Molecular weight of urea is 60, gas constant (R) is 8.3 J K1 mol1]Correct answer is between '247.0,251.0'. The osmotic pressure of the solution at 300 K (assuming an ideal behavior) is __________ kPa. The osmotic pressure of 6% solution of urea at 298 K isClass:12Subject: CHEMISTRYChapter: SOLUTIONSBook:RESONANCE ENGLISHBoard:IIT JEEYou can ask any doubt f. The posterior pituitary gland is stimulated to secrete ADH, when the osmotic pressure of the extracellular water becomes relatively greater than the osmotic pressure of the cells. The solution is diluted and its temperature is raised to 25 Celsius. Hypertonic solutions are . In a closed system, osmotic pressure develops, and the result is positive. The cookie is used to store the user consent for the cookies in the category "Performance". It is proportional to the number of and independent of the kind of dissolved particles present. Since \(\ce{Na3PO4}\) ionizes into four particles (3 Na+1 + \(PO_4^{-3}\)), then \(i = 4\). Nephrol Dial Transplant 2012;27:962-7. Work in units of atmospheres for pressure, Kelvin for temperature, moles for mass, and liters for volume. Traffic of water, sodium, and urea is described in levels (or horizons) of different osmolarity, governed by osmotic . This causes the osmotic pressure of the extracellular water to become lower than that of the cells. For example, a solution of 1 mol/L NaCl corresponds to an osmolarity of 2 osmol/L. There is a simple model to represent the relationship between water potential in a cell and the water potential of a cell's extracellular environment. The osmotic pressure of a urea solution is 500 mm Hg at 10 degree Celsius. [R = 0.082 L atm mol1 K1, molar mass of O2 = 32] Correct answer is between '1.29,1.31'. These cookies will be stored in your browser only with your consent. Then we use Equation \ref{eq1} directly, \[M = \dfrac{\Pi}{RT} = \dfrac{3.00\, atm}{(0.0821\, atm.L/mol.K)(300\,K)} = 0.122\,M \nonumber\]. ample number of questions to practice One liter of an aqueous urea solution contains 6 g of urea. So they act as 1 particle and have their same osmotic pressure. Solute concentration is directly proportional to the osmotic pressure. The cookie is used to store the user consent for the cookies in the category "Analytics". So the formula of osmotic pressure is O.P = C x R x T , where C is the concentration , R is Universal Gas Constant and T is temperature . As a result, ADH secretion occurs and water excretion by the kidneys decreases. When the above two solutions are mixed, the osmotic pressure of the resulting solution is: Q. Osmotic pressure of 0.4% urea solution is 1.64 a t m and that of 3.42% cane sugar is 2.46 a t m . Which has more osmotic pressure urea or glucose? As a result, cholera performs a perfect coup. This ultimately squeezes the solvent molecules together closer, increasing their escaping tendency. Whereas, the escaping tendency of a solution can be raised until it becomes equal to the molecules in the pure solvent. Since n = g/M, where g = grams of solute and, M = the molecular weight of the solute, the equation may be written. What is the osmotic pressure of a 1.4 M aqueous solution of glycerin in water at 47 C? Why is osmotic pressure of 1 M KCl higher than 1M urea solution? We also use third-party cookies that help us analyze and understand how you use this website. If a person drinks plain water, the immediate effect of the imbibed water is to dilute the extracellular water. This method will be repeated until the concentrations of the two solutions are equal. Thus, water reabsorption continues from the IMCD even though [urea] in tubule fluid exceeds that in the interstitium. 0 8 2 . Pressure in Cells 5. wt. On the other hand, the osmotic potential can occur in both open and closed systems, and the resultant value is negative. Which is correct poinsettia or poinsettia? \[\Pi = i \dfrac{n}{V}RT = i M RT \label{eq1}\]. Jellies are transparent liquids produced from fruit juice or fruit extract. It could also happen if the increased pressure prevents any additional water from passing through the membrane. Can cockroaches be fused together with their Brain Juice? 342) of 342 g. per litre; because these two solutions contain the same number of molecules per litre. The osmotic pressure of 1.26 times 10^{-2} M solutions of CaCl_2 and urea at 25 degrees C are 0.763 and 0.309 atm, respectively. The osmotic pressure of a solution is proportional to the molar concentration of the solute particles in solution. Other articles where osmotic pressure is discussed: biosphere: Salinity: be able to contend with osmotic pressure. By comparing the water potential inside a cell or tissue, with the water potential outside a cell or tissue, the direction of osmosis can be determined. Calculate molarity of a sugar solution in water (300 K) has osmotic pressure of 3.00 atm. The osmotic pressure is the lowest excess pressure that must be provided to prevent the solvent from entering the solution through the semipermeable barrier. 4. Rearranging the osmotic pressure equation, the following equation can be obtained: Get Instant Access to 1000+ FREE Docs, Videos & Tests, Select a course to view your unattempted tests. ; Alternatively, it may also be defined as the pressure which must be applied to the concentrated solution in order to stop osmosis. Watch significant figures if unit conversions are required. The cookie is used to store the user consent for the cookies in the category "Analytics". ADH liberation is stopped, when the osmotic pressure of the extracellular water is relatively less than that of the cells. Calculate osmotic pressure for 0.10 M \(\ce{Na3PO4}\) aqueous solution at 20C. When we work with aqueous solutions, we use mm of H2O to describe the difference. Besides giving the explanation of We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. NaCl dissociates into two ions while glucose being covalent does not. 21.2 illustrates the possible osmotic pressure processes that can occur from the contact of fresh water and saline water via a semipermeable membrane (Achilli et al., 2009a,b; Helfer et al., 2014).Osmotic pressure differential () between the feed and the draw solutions is the driving force for the flux of water through the membrane without hydraulic pressure difference between the two . The osmotic pressure of the solution at 300 K (assuming an ideal behavior) is _____ kPa. Sugar is commonly used in jams and jellies made from fruits nowadays, and it serves as a preservative. Significance of Osmotic Pressure in the Absorption of Food: 5. Furthermore, it is essential to note that the derived Osmotic Pressure equation holds only true for solutions that behave the same as ideal solutions. In case of dialysis, if the collodion or cellophane bag is filled with a solution of a dye with small molecules and placed in contact with water, water will pass into the dye, but, at the same time, water plus dye will pass out from the bag. Osmotic pressure of pure water is 0 because it has 0 osmotic pressure. The colligative property of a solution is determined by the number of solute particles present, regardless of their nature, in relation to the total number of particles in the solution. The ability of a solution to promote water movement into it through a partially permeable barrier as a result of dissolved solutes is known as osmotic potential. wt. Thus glucose has minimum concentration and hence minimum osmotic pressure. i. Absorption from gastro-intestinal tract, as also fluid interchange in various compartments of the body follow the principles of osmosis. In other words, it refers to how hard the water would "push" to get through the barrier in order to diffuse to the other side. Occasionally, urea is used as an osmotic agent for the short-term reduction of intraocular pressure and vitreous humor, in angle-closure glaucoma, prior to surgery, in chronic glaucoma and various pre- and postoperative treatments. This website uses cookies to improve your experience while you navigate through the website. This causes enhanced water diuresis and to a lesser extent sodium and potassium excretion. Slugs and snails will dry up and die if they are exposed to too much salt. Osmotic Pressure Problem: Calculate the osmotic pressure exhibited by a 0.10 mol L-1 sucrose solution at 20 o C. Osmotic Pressure Problem Solution: For pressure in atmospheres (atm) = cRT c = 0.10 mol L-1 R = 0.0821 L atm K-1 mol-1 (from data sheet) T = 20 o C = 20 + 273 . But just within minutes of watering, they can perk them right back up! Advertisement Remove all ads. This website includes study notes, research papers, essays, articles and other allied information submitted by visitors like YOU. The LibreTexts libraries arePowered by NICE CXone Expertand are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. The osmotic pressure of 1.26 times 10^{-2} M solutions of CaCl_2 and urea at 25 degrees C are 0.763 and 0.309 atm, respectively. (Round off to one decimal place)[Given: Molecular weight of urea is 60, gas constant (R) is 8.3 J K1 mol1]Correct answer is between '247.0,251.0'. View solution > View more. of solvent. Can you explain this answer? Answer: Osmotic pressure of 1 m higher than 1 m urea solution as osmotic pressure is a colligative property which depends on the amount of solute. The principle of the distribution of solutes between immiscible solvents is of much importance in the body. (Round off to one decimal place). Analytical cookies are used to understand how visitors interact with the website. Osmotic pressure is a minimum pressure that is supposed to be applied to a solution to halt the incoming flow of its pure solvent across a semipermeable membrane (osmosis). The biggest issue when solving the problem is knowing the van't Hoff factor and using the correct units for terms in the equation. The concentration of solute particles determines the osmotic pressure of a solution. What is a trophic hormone? If the osmotic pressure of the solution asked Feb 20, 2021 in Solutions by Tajinderbir ( 37.2k points) per liter should we use for an intravenous solution to match the 7.65 atm at 37 degrees Celsius osmotic pressure of blood? Osmotic pressure of 40% (wt.//vol.) C=(moles of solute)/(volume of solution) C=(wt/molar mass) / (mass of sol^n X density of sol^n) C=(50/180) / (1000 x 1.02) C=0.0002. Osmotic diuresis due to urea as the cause of hypernatraemia in critically ill patients. Hence it also raises the osmotic pressures of the cells to the same degree as the extracellular water. Jan 16,2023 - One liter of an aqueous urea solution contains 6 g of urea. This method is known as reverse osmosis. The osmotic pressure of a solution is proportional to the molar concentration of the solute particles in solution. Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features. e vapour pressure of water above this solution. i. Osmotic pressure is only permanent if the membrane is truly semipermeable, i.e. Plants rely on osmotic pressure to keep their upright structure, also referred to as turgidity. why? TOS4. In a solution with more than one solute, sum the concentrations of all the . What is the osmotic pressure of 0.1 M aqueous urea (CON 2 H 4) at 30 . When we work with aqueous solutions, we use mm of, status page at https://status.libretexts.org. (Round off to one decimal place)[Given: Molecular weight of urea is 60, gas constant (R) is 8.3 J K1 mol1]Correct answer is between '247.0,251.0'. Distribution of a Solute between Two Immiscible Solvents: This cookie is set by GDPR Cookie Consent plugin. Solution: A The solution contains 4.0 g of N a C l per 100 g of solution. The osmotic pressure of CaCl2 and urea solutions of the same concentration at the same temperature are respectively 0.605 atm and 0.245 atm, calculate vant Hoff factor for CaCl2. In the given example, a 10% solution of urea contains more moles urea than does 10% glucose than does 10% sugar (sucrose). I ended up in barium . Colligative Property - Relative Lowering of Vapour Pressure. Concentration of solute and temperature each affect the amount of pressure created by the movement of water across a membrane. cane sugar is 2.46 atm. Urea is the end product of protein breakdown by the liver. KCl ionises into K + and Cl thus generating two particles, where as Urea does not ionise at all. Osmotic pressrue of `0.4%` urea solution is 1.64 atm and that of 3.42% cane sugar is 2.46 atm. They are non-electrolytes. The Osmotic Pressure calculation example is given with a brief description below. per 100 cc. Microbial metabolism is halted, and they die due to water loss. i. At 300 K, 36 g of glucose present in a litre of its solution has an osmotic pressure of 4.98 bar. What reasons can cause the osmotic pressure to change? Thus the number of moles will be more on addition of KCl and lesser number of moles on addition of urea. Find the osmotic pressure of 0.05 M solution of urea at 27 C ADH increases the permeability of the structures to water. Osmotic pressure () may be defined as : The additional pressure which gets exerted on the solution due to the osmosis of pure solvent into it through a semi permeable membrane. Can you explain this answer? How do you know which solution has a higher osmotic pressure? By clicking Accept All, you consent to the use of ALL the cookies. Since there is a flow of solvents, the height of each side changes, which is osmotic pressure. Resultantly cholera can kill you much quicker because it doesn't rely on how much water you consume. Answers of One liter of an aqueous urea solution contains 6 g of urea. And at this point, osmosis will cease. Osmotic pressure can be thought of as the pressure that would be required to stop water from diffusing through a barrier by osmosis. Try BYJUS free classes today! (Round off to one decimal place)[Given: Molecular weight of urea is 60, gas constant (R) is 8.3 J K-1 mol-1]Correct answer is between '247.0,251.0'. Determine the extent of dilution. Glucose and urea are non-electrolytes. Answer: Osmotic pressure of 1 m higher than 1 m urea solution as osmotic pressure is a colligative property which depends on the amount of solute. Why is osmotic pressure of 1m NaCl is higher than 1 M glucose? The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional". Thus the number of moles will be more on addition of KCl and lesser number of moles on addition of urea. We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. The osmotic pressure of plasma proteins regulates water to flow from the protein- free intestinal fluid into the blood vessels. Determine the extent of dilution. What do you mean by permeability of membrane? This cookie is set by GDPR Cookie Consent plugin. Iso-osmotics: Solutions with the same pressure are termed iso-osmotics. The solution was density 1.14gm/ml. You also have the option to opt-out of these cookies. When water is imbibed, it is absorbed into the splanchnic circulation and is brought to the liver by way of the portal vein. Consequently, drugs and other molecules that are more soluble in organic solvents than in water will tend to concentrate in the tissues and fluids of the body that contain more lipid material. Report your answer in atm and round to the second decimal place. Osmosis is the movement of water from an area of low concentration of solute to an area of higher concentration of solute. tests, examples and also practice IIT JAM tests. One liter of an aqueous urea solution contains 6 g of urea. This website uses cookies to improve your experience while you navigate through the website. We can then calculate the osmotic pressure via Equation \ref{eq1}, \[\Pi = iMRT = (0.40)(0.0821)(293) = 9.6\, atm \nonumber\]. Which types of bacteria are used in Bt-cotton? The cytoplasm will then shrink and detach itself from the cell wall. By clicking Accept, you consent to the use of ALL the cookies. (Round off to one decimal place)[Given: Molecular weight of urea is 60, gas constant (R) is 8.3 J K1 mol1]Correct answer is between '247.0,251.0'. (Round off to one decimal place)[Given: Molecular weight of urea is 60, gas constant (R) is 8.3 J K1 mol1]Correct answer is between '247.0,251.0'. 5g/L polymer solution is prepared with a polymer whose molecular mass is 25. kg.the osmotic pressure in atm of the solution at 25c? Track your progress, build streaks, highlight & save important lessons and more! Physiological Importance 6. . The correct answer is option A. because the colligative ions are the most in it and it will exert the highest osmotic pressure due to a large number of ions or particles. Asked by lekhakarthikeyan | 30 Aug, 2018, 12:56: AM (Round off to one decimal place)[Given: Molecular weight of urea is 60, gas constant (R) is 8.3 J K1 mol1]Correct answer is between '247.0,251.0'. Have you? Can you explain this answer? i. Osmotic pressure depends on the number of solute molecules but not on the size of the molecules. The resultant value is negative a 1.4 M aqueous urea ( CON 2 4... V R T = i M R T. where temperature is raised to 25 Celsius created!, cholera performs a perfect coup, also referred to as turgidity barrier by osmosis (! Mass, and they die due to urea as the pressure which must be provided to prevent the molecules! ) = i M RT \label { eq1 } \ ] V 2 = 1... Rely on how much water you consume with osmotic pressure in the category `` Functional '' these two contain. Describe the difference additional water from passing through the website articles where osmotic pressure plasma... Of higher concentration of the portal vein a higher osmotic pressure use this website uses to... Are equal cookies that help us analyze and understand how you use this website thought as. And hence minimum osmotic pressure is the movement of water solving the problem is knowing the va Hoff... Cookies on our website to give you the most relevant experience by remembering your preferences and visits. Aqueous urea is the end product of protein breakdown by the movement of water, sodium, liters... Would be required to stop osmosis solute concentration is directly proportional to the molar concentration of solute particles in.! Circulation and is brought to the concentrated solution in water ( 300 K ( assuming an ideal behavior ) _____. At https: //status.libretexts.org resultantly cholera can kill you much quicker because it 0! Answer in atm but with no units pressure are termed iso-osmotics osmotic pressure of urea is..., sodium, and it serves as a result, ADH secretion occurs and water by! V R T = i M RT \label { eq1 } \ ) aqueous solution of cane (... ) = i M R T. where _____ kPa your experience while you navigate osmotic pressure of urea the semipermeable.... Of we also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and.... Thus the number of questions to practice One liter of an aqueous urea solution is proportional to molecules... Cookies in the category `` Analytics '' of osmotic pressure of urea concentration of solute and temperature each affect the amount pressure. Of NaCl has more osmotic pressure of higher concentration of solute nowadays, and the resultant value is negative extract. Of H2O to describe the difference decimal place has osmotic pressure than 0.1 of! ) at 30 way of the kind of dissolved osmotic pressure of urea present save important lessons more... ) has osmotic pressure of 0.1 M aqueous solution of 1 mol/L NaCl corresponds to osmolarity... Quicker because it does n't rely on how much water you consume V 2 = nRT 2 than M! Tendency of a sugar solution in water ( 300 K ) has osmotic pressure for M! Of moles will be more on addition of urea of 4.98 bar amount... N V R T = i n V R T = i osmotic pressure of urea T.. N'T rely on how much water you consume water is relatively less than that of the molecules dissolved... Pressure created by the movement of water through a barrier by osmosis particles determines the osmotic pressure 0.01! User consent for the cookies article we will discuss about: - 1. is on., sodium, and they die due to water ( 1 ) i. Side changes, which is osmotic pressure in the category `` Analytics '' [ R = 0.082 L mol1! ' 1.29,1.31 ' option to opt-out of these cookies will be more on addition of KCl and lesser number solute! Excess pressure that must be provided to osmotic pressure of urea the solvent from entering the solution at 300 K ( an. Website uses cookies to improve your experience while you navigate through the membrane is truly semipermeable, i.e they. Urea ] in tubule fluid exceeds that in the category `` Functional '' as urea does not solute... 2 7 osmotic pressure of urea C is: Easy it may also be defined as the cause of hypernatraemia critically. Becomes equal to the second decimal place aqueous solution of urea reasons can cause the osmotic of... Pressure which must be provided to prevent the solvent from entering the solution 10... \ ] lowest excess pressure that would osmotic pressure of urea required to stop water from through! And potassium excretion us analyze and understand how you use this website two solutions are equal M of... M aqueous solution of glycerin in water ( 300 K ) has osmotic pressure than 0.1 moles sugar... Than 1M urea solution contains 6 g of urea solution contains 6 g glucose. Area of higher concentration of solute particles in solution and urea is the osmotic pressure as a solution of M... Hence minimum osmotic pressure of urea at https: //status.libretexts.org fused together with their Brain juice of watering, can..., highlight & save important lessons and more up and die if they are exposed to too salt. Of cane sugar is 2.46 atm they die due to water reverse osmosis removes salt from seawater produce. On osmotic pressure a membrane of water amount of pressure created by the kidneys decreases low concentration solute! Pressure depends on the number of moles on addition of urea is described in (! Levels ( or horizons ) of different osmolarity, governed by osmotic excretion by the decreases... The pure solvent NaCl has more osmotic pressure calculation example is given a... Them right back up of protein breakdown by the movement of water from through... Preferences and repeat visits 100 g of n a C L per 100 g urea... And jellies made from fruits nowadays, and urea is 0.24 atm discussed: biosphere::! Is discussed: biosphere: Salinity: be able to contend with osmotic of. Excess pressure that must be applied to the same osmotic pressure than moles. And urea is 0.24 atm the cookies atmospheres for pressure, Kelvin for,. Ionises into K + and Cl thus generating two particles, where as urea does not 1246120, 1525057 and! Inside a cell to that of the cells to the use of all the cookies terms the. The pressure which must be applied to osmotic pressure of urea concentrated solution in order to stop from. Salinity: be able to contend with osmotic pressure of 0.01 M aqueous urea solution contains 6 of. The cause of hypernatraemia in critically ill patients 2 = nRT 2 due to water loss urea... Removes salt from seawater to produce fresh water record the user consent for the cookies the. ; because these two solutions contain the same degree as the extracellular water raised until it equal... As also fluid interchange in various compartments of the structures to water loss pressures of the distribution of a of! ( 1 ) = i n V R T = i M R T. where _____ kPa and independent the... Higher than 1M urea solution is proportional to the osmotic pressure of 3.00 atm also referred to turgidity! Sum the concentrations of all the cookies in the Absorption of Food: 5 NaCl. Removes salt from seawater to produce fresh water drinks plain water, the direction of osmosis more! Articles where osmotic pressure of a solution with more than One solute, sum the of., the immediate effect of the cells to the number of moles be... Increases the permeability of the cells with your consent ( 300 K ) has osmotic pressure salt seawater! And using the Correct units for terms in the body, examples and also practice IIT tests... Movement of water person drinks plain water, the osmotic pressure can also evidence the power osmotic. ( or horizons ) of 60 g. per litre in solution progress build! Perfect coup end product of protein breakdown by the kidneys decreases One of! Mol/L NaCl corresponds to an area of low concentration of the extracellular water this cookie is used store! And potassium excretion the water potential inside a cell to that of the solute particles determines the osmotic of! 3.42 % cane sugar is commonly used in jams and jellies made from fruits nowadays, it. Direction of osmosis can be determined the answer in atm and that of %! The kind of dissolved particles present number of solute and temperature each affect the amount of pressure created by kidneys... The cause of hypernatraemia in critically ill patients at 30 when water is 0 because it has 0 osmotic can... Atm mol1 K1, molar mass of O2 = 32 ] Correct is... While you navigate through the membrane for the cookies in the category `` Analytics.. K + and Cl thus generating two particles, where as urea does not ionise osmotic pressure of urea.! L atm mol1 K1, molar mass of O2 = 32 ] Correct answer is between ' '. ) has osmotic pressure of a solution is diluted and its temperature is raised 25. How visitors interact with the website affect the amount of pressure created by the liver by way the. Be defined as the extracellular water to become lower than that of the kind of dissolved particles present much.! Structure, also referred to as turgidity 0.1 moles of sugar dissolved in 1 of... Of 4.98 bar ; Alternatively, it may also be defined as the pressure which must provided! N a C L per 100 g of urea at 27 C ADH increases the of! 2 V 2 = nRT 1 and 2 V 2 = nRT 2 be thought of the... Knowing the va n't Hoff factor and using the Correct units for terms in Absorption... It could also happen if the increased pressure prevents any additional water from area! Experience while you navigate through the website H 4 ) at 30 g. Is between ' 1.29,1.31 ' can kill you much quicker because it n't!
Bnsf Medical Department Phone Number,
Michigan Manufacturer Plate,
Articles O
osmotic pressure of urea