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How do you make 50mM ammonium acetate solution?
One mole of ammonium acetate is equal to 77.08g (this is the formula weight, FW, of ammonium acetate, which can be found on the side of the bottle). Another way of representing this is 77.08/mol (so, in one mole of ammonium acetate, there are 77.08grams of ammonium acetate).We have to use the FW value to calculate molarity (moles of solute per L of solvent).I am not sure what volume of the 50mM solution is desired, so I will assume that you need 1 L.50mM is equal to 50milli-moles of solute/1 L of solvent, which is the same as 0.05moles/L. This is what the math looks like:77.08g/mol ammonium acetate x 0.05mol/L = 3.854g/LSo, to make a 50mM solution of ammonium acetate in 1L of water, you will need to dissolve 3.854g of ammonium acetate into 1L of water.
How do you adjust pH of ammonium acetate solution to?
You can adjust the pH of an ammonium acetate solution by adding a strong acid (such as hydrochloric acid) to lower the pH or a strong base (such as sodium hydroxide) to raise the pH. Use a pH meter to monitor the pH levels during the adjustment process until you reach the desired pH value.
What is meant by Sodium acetate is a basic salt?
Sodium acetate is called a basic salt because a solution of it in initially pure water has a pH value well above the neutral value of 7. This occurs because acetate ions when dissolved in water must come to an equilibrium in the ionic reaction C2H3O2-1 + H2O <-> C2H4O2 + OH-1 and sodium ions when dissolved in water must come to an equilibrium in the ionic reaction Na+1 + H2O <-> NaOH + H+1. Additionally, water itself must maintain an equilibrium in the ionic reaction H2O <-> H+1 + OH-1. The values of these three equilibrium constants are such that the net result is a higher concentration of hydroxide ions than of hydrogen ions in a solution of sodium acetate. These relative concentrations of hydroxide and hydrogen ions is the defining characteristic of a basic (or alkaline) aqueous solution: Such a relative concentration of hydroxide and of hydrogen ions, although not all the other characteristics of a sodium acetate solution, could be achieved by dissolving an appropriate amount of the base sodium hydroxide in initially pure water.
What is the solution's freezing point depression?
To solve freezing point depression problems, you need to know the following things:-- the identity of the solute (the thing you are adding to the liquid)-- the identity of the solvent (the liquid)-- whether the solute is molecular or ionic, and if ionic, how many ions it forms-- the amount of solute (in grams or moles)-- the amount of solvent (in kilograms)-- the value of Kf of the solvent (for water, it is -1.858 K·kg/mol (or -1.858 °C molal-1)Then you use the following equation:∆T = i * Kf * mwhere ∆T is the change in the freezing point, "i" is the number of molecules or ions formed upon addition to the solvent, Kf is the freezing point depression constant, and "m" is the molality of the solution.The Kf of water for a freezing point depression is known and is equal to -1.858 °C·kg/mol (or -1.858 °C molal-1)The value of "i" has to do with what you add to the water. If you added sugar, a molecular compound the value of "i" is 1.0. If you add a ionic compound like NaCl, the value of "i" is 2.0 because for every 1 molecule of NaCl, you make 2 ions: one Na+ and one Cl- in water. For MgCl2, the value of "i" is thus 3.0 (for each MgCl2 you get one Mg2+ and two Cl- ions, so a total of 3 ions).To find "m," the molality of a solution you need to know the number of moles of solute and the number of kilograms of solvent (m = moles/kg). If you are given the number of grams of solute, the number of moles is found from the mass and the molar mass of the solute.grams of solute ÷ molar mass of solute = moles of soluteTo find the molality, just divide the moles of solute by the kilograms of solvent moles of solute ÷ kilograms solvent = molality Note: If you are given the volume of the solvent instead of the mass, use the density of the solvent to convert -- the density of water is 1 kilogram per liter)Liters of solvent * density of solvent = kilograms of solventNow just plug all the numbers into the equation at the top of the answer!
How do you prepare 250ml 0.1M sodium acetate buffer pH 4.5?
7.4 ml of 0.2 molar acetic acid and17.6 ml of 0.2 molar sodium acetate made up with water to a total volume of 100 ml will have a pH of 5. The total acetate concentration (that is, acetate ions plus non-disocciated acetic acid) will be 50 mM. However, the concentration of acetate ions will be lower than 50 mM, but its value could be calculated with the Henderson-Hasselbalch equation. This is derived from the following source: @INCOLLECTION{Gomori1955, author = {G. Gomori}, title = {Preparation of buffers for use in enzyme studies}, booktitle = {Preparation and assay of enzymes}, publisher = {Academic Press, Inc, New York}, year = {1955}, editor = {Sidney .P. Colowick and Nathan.O. Kaplan}, volume = {I}, series = {Methods in enzymology}, chapter = {16}, pages = {138--146}, keywords = {buffers}, url = {http://microscopy.berkeley.edu/Resources/instruction/buffers.html}, } The acetate buffers table in Chapter 10 of the same Volume may also be helpful.
What solvent system would give the highest Rf value for acetophenone?
A non-polar solvent system, such as hexanes and ethyl acetate, would provide the highest Rf value for acetophenone since it is a non-polar compound. The non-polar solvent system will have less affinity for the polar silica gel in the TLC plate, allowing the acetophenone to move further up the plate during the chromatography process.
What is the Rf value of salicylamide?
It will depend on the solvent system you are using.
What is the RF value for paracetamol?
That depends on many factors including the elution solvent used, the type of TLC plate used, etc.. When using .5% of acetic acid in ethyl acetate as your elution solvent and on a plastic backed plate, the Rf-value should be around 79.82%
What is solvent for benzil to develop TLC and Rf?
A common solvent mixture for developing TLC plates with benzil as the compound is a mixture of ethyl acetate and hexane in a 1:1 ratio. This solvent system can help achieve good separation and clear Rf values for benzil on the TLC plate.
What is the RF value of benzoic acid in ethyl acetate?
The RF value of benzoic acid in ethyl acetate is 0.68.
What is Rf value of o-nitroaniline?
The Rf value will vary some depending on the exact conditions. Using a silica plate and a moderately polar solvent (dichloromethane or a mixture of toluene/ethyl acetate) you will get an Rf of 0.4-0.5.
How do you make 50mM ammonium acetate solution?
One mole of ammonium acetate is equal to 77.08g (this is the formula weight, FW, of ammonium acetate, which can be found on the side of the bottle). Another way of representing this is 77.08/mol (so, in one mole of ammonium acetate, there are 77.08grams of ammonium acetate).We have to use the FW value to calculate molarity (moles of solute per L of solvent).I am not sure what volume of the 50mM solution is desired, so I will assume that you need 1 L.50mM is equal to 50milli-moles of solute/1 L of solvent, which is the same as 0.05moles/L. This is what the math looks like:77.08g/mol ammonium acetate x 0.05mol/L = 3.854g/LSo, to make a 50mM solution of ammonium acetate in 1L of water, you will need to dissolve 3.854g of ammonium acetate into 1L of water.
What are some possible explanations to why melting point of your isolated caffeine was lower than the literature value?
Melting points should always be reported as a range. Maybe during purification process was not perfect, and there were impurities in the caffeine that were affecting the melting point. The melting point is depressed due to impurities in the sample. The caffeine is usually not 100% pure, maybe improper isolation procedure and also the impurity is likely solvent.
What is rf value and how is determine?
the mobility of any component in a particular solvent is referred to as its RF value. Mathematically, RF value = distance travelled by solute/ distance travelled by the solvent
What is the pH of value CH3COONa?
The water solution of sodium acetate has a basic pH.
Which combination of solute and solvent polarity will result in the largest RF value?
A combination of a nonpolar solute and a polar solvent will result in the largest RF value.
What do the Rf values indicate about the relative solubility of the pigment in the the solvent?
The Rf values do not indicate the solubility of a substance. The Rf value or retardation factor is the ratio of the distance traveled by the center of a pot to the distance traveled by the solvent front in chromatography.
