Question

What fraction of water and ethanol should be used to prepare a 4 mg/mL solution of a drug that has the solubility of 0.2 and 24 mg/mL in water and ethanol, respectively? (please explain each step)

Answer #1

We need to prepare a 4 mg/mL solution of a drug. Thus 1 mL of solution will have 4 mg of drug.

Let 1 mL of this solution will have x mL of water. 1-x mL of ethanol will be present.

The drug has the solubility of 0.2 and 24 mg/mL in water and ethanol, respectively.

In x mL of water, the amount of drug present is 0.2 x mg. In (1-x) mL of ethanol, the amount of drug present is 24 (1-x) mg. The total amount of drug is 0.2 x + 24 (1-x) which is equal to 4 mg

Thus we have 0.84 mL water and mL ethanol.

The fraction of water and ethanol is

If 12 mg of ethanol are dissolved in 25 mL of water
a. what are the mol fractions of the two liquids in the mix
b.the vapor pressures of pure ethanol and water at 25 C are
respectively 58.9 and 23.8 Torr. Calculate the vapor pressure of
the mix, assuming ideality
c. once the liquid has reached equilibrium with the vapor, what
will the mol fraction of the two liquids in the vapor phase be?

A solution of ethanol (C2H6O) in water is sometiems used as a
disenfectant. 1.00 L of this solution contains 553 g of ethanol and
335 g of water. What is the mole fraction of ethanol in this
solution? *show all work and calculations

A solution of ethanol (d=0.795 g/mL) and water (H2O) is prepared
by placing 30.0 mL of ethanol in a 250.0 mL volumetric flask and
diluting with water to the flask etched mark . (a) what is the
molarity of the ethanol in this solution? (b) Next, 25.o mL of the
solution above is diluted to a final volume of 500.0 mL, what is
the new molarity of the diluted solution?

A solution is 40% ethanol (density = 0.789 g/mL) by volume and
60% water (density = 1.00 g/mL). If Tom Titan has 750.0 mL of the
solution, what is the mass of ethanol in solution?

A solution is made by mixing 36.0 mL of ethanol, C2H6O, and 64.0
mL of water. Assuming ideal behavior, what is the vapor pressure of
the solution at 20

Prepare 500mL of a 4% solution by diluting a 20% solution with
water. What is the volume of drug and volume of diluent?

A solution is made by mixing 49.0 mL of ethanol, C2H6O, and 51.0
mL of water. Assuming ideal behavior, what is the vapor pressure of
the solution at 20 °C?

Vodka is 25% by mass ethanol (C2H5OH) and
has a density of 0.75 g/mL. Calculate the mole fraction of each
species (water and ethanol) in solution, and the molality of the
ethanol in vodka.

The density of a 40 wt% solution of ethanol in water is 0.937
g/mL. The density of n-butanol is 0.810 g/mL. What is the
concentration of n-butanol in ppm if you dissolve 15 μL of this
alcohol in a 40 wt% solution of Ethanol in water. The final volume
of the solution is 25 mL. Assume that the density of the ethanol
solution does not change upon dissolution of the butanol. Use the
correct number of significant figures!

You isolate a subcellular fraction and find the protein
concentration to be 40 mg/mL.
a) Show all calculations and explain how you would prepare 50
µL of a 4 mg/mL final concentration after dilution in 2X sample
buffer. (Final concentration after mixing with 2X sample should be
4 mg/mL).
b) You are asked to load 20 µg total proteins into a well in
the polyacrylamide gel. How many microlitres of the sample prepared
above should you load onto the gel?

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 2 minutes ago

asked 23 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago