Because Na has MW of ~23 and Cl has MW of ~35...both of which are small enough to pass through a molecular weight cut off (MWCO) of 50 (don't add there molecular weights together). urea has ~ MW of 60 so it's too big to cross membrane.
Sodium chloride (NaCl) has a higher boiling point than urea. This is because sodium chloride forms ionic bonds which are stronger than the hydrogen bonds in urea. Stronger bonds require more energy to break, resulting in a higher boiling point.
Diazolidinyl urea is produced by the chemical reaction of allantoin and formaldehyde in the presence of sodium hydroxide solution and heat. The reaction mixture is then neutralized with hydrochloric acid and evaporated. Note: Diazolidinyl urea is an antimicronbial preservative used in cosmetics. It is chemically related to imidazolidnyl urea which is used in the same way. Diazolidinyl urea acts as a formaldehyde releaser. Commercial diazolidinyl urea is a mixture of different formaldehyde addition products including polymers. source: http://en.wikipedia.org/wiki/Diazolidinyl_urea
No, urea crystals are not an element. Urea is a compound composed of carbon, nitrogen, oxygen, and hydrogen atoms.
NH2CONH2 is the chemical formula for urea, a compound found in urine and used in fertilizers, cosmetics, and as a raw material for plastics and resins. It is produced in the liver as a way to remove excess nitrogen from the body.
Phenolic resin is made by the reaction between phenol and formaldehyde, whereas urea formaldehyde resin is made by the reaction between urea and formaldehyde. Phenolic resin offers higher heat resistance and better moisture resistance compared to urea formaldehyde resin. Urea formaldehyde resin is typically more cost-effective and has better flexibility than phenolic resin.
Urea has a molecular weight lower than 20 MWCO, so it should be able to diffuse through a 20 MWCO membrane. If urea is not able to diffuse through a 20 MWCO membrane, it may be due to factors like the membrane being damaged or having a different pore size than expected, or the presence of additional physical or chemical barriers that prevent urea diffusion.
The 20 MWCO membrane has a molecular weight cutoff that is lower than the molecular weight of urea, preventing urea from passing through the pores of the membrane. This size exclusion property of the membrane hinders the diffusion of urea molecules across it.
The average diffusion rate of urea through a 200 MWCO (Molecular Weight Cut-Off) membrane would depend on various factors such as concentration gradient, temperature, and membrane properties. Typically, higher MWCO membranes allow for faster diffusion rates of smaller molecules like urea due to their larger pore sizes. Specific experimental data would be needed to calculate the exact diffusion rate in this scenario.
These substances have different molecular sizes and charges, which can affect their ability to penetrate the cell membrane. For example, glucose and urea are small molecules and can easily pass through the membrane, causing osmosis to occur. In contrast, NaCl, ammonium chloride, and larger molecules may not pass through as easily and lead to different osmotic effects on RBCs.
First of all, the filtration in dialysis doesn't happen in the tubing. Rather it happens in an artificial kidney called the dialyzer. It's essentially a dense bundle of thousands of fibers which make up the filter itself. The fibers allow the blood to pass through the dialyzer and the potassium and bicarbonate solution used to mix with the blood crosses over the fibers, cleaning the blood via filtration. MWCO (molecular weight cut off) in dialysis simply means the amount of molecules that are allowed to pass through the membranes. Proteins are too big to pass by design as we don't want to "wash away" the good stuff. Wastes like urea, nitrogen etc are allowed to pass through and out of the blood before the blood returns to the patient. Generally, the bigger the patient, the more filtration is required, so the higher the MWCO is. Hope this helps!
NaCl will not harm RNA. In fact, it is sometimes used as an elution buffer for RNA-Urea gels.
In order to compare the molality of two solutions, you need to consider the number of particles the solute separates into in a solution. Urea (CH4N2O) separates into one particle in solution, while NaCl separates into two particles. Therefore, 1 molal urea solution is equal to 0.5 molal NaCl solution because NaCl produces twice as many particles in solution as urea.
Urea is produced in the liver as a waste product of protein metabolism. It is then filtered by the kidneys, where it is excreted in urine. Urea helps regulate the body's nitrogen balance and helps to remove toxic ammonia from the body.
As the dialysis fluid has no urea in it, there is a large concentration gradient - meaning that urea moves across the partially permeable membrane, from the blood to the dialysis fluid, by diffusion. This is very important as it is essential that urea is removed from the patients' blood.
Sodium chloride (NaCl) has a higher boiling point than urea. This is because sodium chloride forms ionic bonds which are stronger than the hydrogen bonds in urea. Stronger bonds require more energy to break, resulting in a higher boiling point.
The Kidneys, where the blood/urea thing takes place.
Excess nitrogen is converted into urea by the liver through a process called the urea cycle. Urea is then excreted in urine by the kidneys to maintain nitrogen balance in the body.