How to Calculate Osmotic Pressure
Mar 25, · Multiply the mass of the solute by its molar mass conversion factor. In this instance, the molar mass of NaCl is g, so the conversion factor is 1 mol / g. Moles NaCl = g NaCl * (1 mol / g) = mol = mol. Aug 20, · The biggest issue when solving the problem is knowing the van't Hoff factor and using the correct units for terms in the equation. If a solution dissolves in water (e.g., sodium chloride), it's necessary to either have the van't Hoff factor given or else look it up.
The osmotic pressure of a solution is the minimum amount of pressure needed to prevent water from flowing into it across a semipermeable membrane. Osmotic pressure also reflects how readily water can enter the solution via osmosis, as across a cell membrane. For a dilute solution, osmotic pressure obeys a form of the ideal gas law and can be calculated provided you know the concentration of the solution and the temperature.
What is the osmotic pressure of a solution prepared by adding Solution: Osmosis and osmotic pressure are related. Osmosis is the flow of a solvent into a solution through a semipermeable membrane. Osmotic pressure is the pressure that stops the process of osmosis. Osmotic pressure is a colligative property of a substance since it depends on the concentration of the solute and not its chemical nature. Use the atomic weights to find the molar mass of the compound. Multiply the subscripts in the formula times the atomic weight of the element.
If there is no subscript, it how to change my router settings one atom is present. Remember, absolute temperature is always given in Kelvin. If the temperature is given in Celsius or Fahrenheit, convert it to Kelvin. To find the osmotic pressure, plug the values into the equation.
The biggest issue when solving the problem is knowing the van't Hoff factor and using the correct units for terms in the equation. If a solution dissolves in water e. Work in units of atmospheres for pressure, Kelvin for temperature, moles for mass, and liters for volume. Watch significant figures if unit conversions are required. Share Flipboard Email.
Todd Helmenstine. Todd Helmenstine is a science writer and illustrator who has taught physics and math at the college level. He holds bachelor's degrees in both physics and mathematics. Updated August 20, Cite this Article Format. Helmenstine, Todd. How to Calculate Osmotic Pressure. Calculate What type of body do i have quiz Pressure Example Problem.
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A double replacement reaction will occur if a formation of a precipitate, gas or water takes place. Select two compounds above and this calculator will predict whether or not the reaction will occur in ledidatingstory.com is simply based on the solubility chart of inorganic compounds. where N is the Avogadro constant, g is the Lande g-factor, and ? B is the Bohr magneton. In this treatment it has been assumed that the electronic ground state is not degenerate, that the magnetic susceptibility is due only to electron spin and that only the ground state is thermally populated. Oct 06, · In the empirical formula hydrogen weighs grams. Dividing by we see that the amount of hydrogen needed is twice as much. Therefore the empirical formula needs to be increased by a factor of two (2). The answer is: H 2 C 2 N 2. Density Density refers to the mass per unit volume of a substance. It is a very common term in chemistry.
Stoichiometry Stoichiometry is simply the math behind chemistry. Given enough information, one can use stoichiometry to calculate masses, moles, and percents within a chemical equation. In chemistry, we use symbols to represent the various chemicals. Success in chemistry depends upon developing a strong familiarity with these basic symbols. For example, the symbol "C"represents an atom of carbon, and "H" represents an atom of hydrogen.
To represent a molecule of table salt, sodium chloride, we would use the notation "NaCl", where "Na" represents sodium and "Cl" represents chlorine. We call chlorine "chloride" in this case because of its connection to sodium.
You should have reviewed naming schemes, or nomenclature , in earlier readings. A chemical equation is an expression of a chemical process.
Since they undergo a chemical process, they are changed fundamentally. Often chemical equations are written showing the state that each substance is in. The s sign means that the compound is a solid. The l sign means the substance is a liquid. The aq sign stands for aqueous in water and means the compound is dissolved in water. Finally, the g sign means that the compound is a gas.
Coefficients are used in all chemical equations to show the relative amounts of each substance present. This amount can represent either the relative number of molecules , or the relative number of moles described below. If no coefficient is shown, a one 1 is assumed. On some occasions, a variety of information will be written above or below the arrows. This information, such as a value for temperature, shows what conditions need to be present for a reaction to occur.
The graphic below works to capture most of the concepts described above: The Mole Given the equation above, we can tell the number of moles of reactants and products. A mole simply represents Avogadro's number 6. A mole is similar to a term like a dozen. If you have a dozen carrots, you have twelve of them. Similarly, if you have a mole of carrots, you have 6. In the equation above there are no numbers in front of the terms, so each coefficient is assumed to be one 1.
Converting between moles and grams of a substance is often important. Given the atomic or molecular mass of a substance, that mass in grams makes a mole of the substance. For example, calcium has an atomic mass of 40 atomic mass units.
So, 40 grams of calcium makes one mole, 80 grams makes two moles, etc. Balancing Chemical Equations Sometimes, however, we have to do some work before using the coefficients of the terms to represent the relative number of molecules of each compound.
This is the case when the equations are not properly balanced. If this were the case, the reaction would be quite spectacular: an aluminum atom would appear out of nowhere, and two 2 iron atoms and one 1 oxygen atom would magically disappear.
We know from the Law of Conservation of Mass which states that matter can neither be created nor destroyed that this simply cannot occur. We have to make sure that the number of atoms of each particular element in the reactants equals the number of atoms of that same element in the products. To do this we have to figure out the relative number of molecules of each term expressed by the term's coefficient. Balancing a simple chemical equation is essentially done by trial and error. There are many different ways and systems of doing this, but for all methods, it is important to know how to count the number of atoms in an equation.
For example we will look at the following term. In each molecule of this substance there are three 3 Fe atoms. Therefore in two 2 molecules of the substance there must be six 6 Fe atoms. Similarly there are four 4 oxygen atoms in one 1 molecule of the substance so there must be eight 8 oxygen atoms in two 2 molecules. Count the number of each atom on the reactant and on the product side. Determine a term to balance first. When looking at this problem, it appears that the oxygen will be the most difficult to balance so we'll try to balance the oxygen first.
On the reactant side, we have a coefficient of three 3 multiplied by a subscript of four 4 , giving 12 oxygen atoms. On the product side, we have a coefficient of four 4 multiplied by a subscript of three 3 , giving 12 oxygen atoms.
Now, the oxygens are balanced. Choose another term to balance. We'll choose iron, Fe. Since there are nine 9 iron atoms in the term in which the oxygen is balanced we add a nine 9 coefficient in front of the Fe.
In this case, since we had eight 8 aluminum atoms on the product side we need to have eight 8 on the reactant side so we add an eight 8 in front of the Al term on the reactant side.
That is called the "limiting reagent". Often, it is necessary to identify the limiting reagent in a problem. Example: A chemist only has 6. If she uses the equation below, how much oxygen should she add to the reaction? First, we calculate the number of moles of C 2 H 2 in 6. To be able to calculate the moles we need to look at a periodic table and see that 1 mole of C weighs Oxygen: 3.