Question

A
1% w/v solution of drug X had a freezing point depression of 0.92
Celsius. At what percent strength of drug X isotonic? Use 2 sig
figs

Answer #1

Benzene has a normal freezing point of 5.50°C and a molal
freezing point depression constant of 5.12°C/m. A solution prepared
by dissolving 0.335g of compound X in 5.00g of benzene has a
freezing point of 1.34°C. Assuming that compound X is a
nonelectrolyte, what is the molar mass of compound X?

Freezing Point Depression Lab
Objective: To use freezing point to determine the molecular
weight of an unknown substance.
In this lab, we used benzophene as the solvent, which has a
freezing point of 48.1 degrees celsius and Kf value of 9.80 degrees
C/m. The procedure consisted of measuring out 10 g benzophenone in
a test tube and melting the substance in a warm water bath. When
melted, we removed the test tube from the bath and allowed it to
cool....

How many mol of NaOH are in 0.55 mL of 25%w/v NaOH solution?
(Report your answer to 2 sig figs.)

5. Determine the molal freezing point depression constant (Kf)
(in °C⋅kg/mol) of water by using the data of three NaCl solutions .
Use Equation 3 in the “Background and Procedure” file, the molality
values of all solutes from Question s 1 – 3 and the freezing point
depression ( ∆T) from Question 4. In your calculation, rewrite the
symbol“m ” (the molality) as “mol/kg” so that the molal freezing
point depression constant will have the correct unit. Make
sure to...

A certain substance X has a normal freezing point of -6.4 C and
a molal freezing point depression constant Kf= 3.96
degrees C.kg.mol-1. A solution is
prepared by dissolving some urea ((NH2)2CO)
in 950. g of X. This solution freezes at -13.6 C. calculate the
mass of urea that was dissolved. Round your answer to 2 significant
digits.

1. If 480 mL of a 30% w/v solution were diluted to 2.5 liters,
what would be the percentage strength (w/v)? Express units only as
%. (Round to tenths)
2. If 3 tablepoonsful of povidone iodine solution (6.0 % w/v)
were diluted to 1.50 pint with purified water, what would be the
ratio strength (w/v, which is what the units are for this
problem) of the dilution [expressed as 1:____ rounded to the
nearest whole number and without putting the...

The boiling point of an aqueous solution is 101.88 °C. What is
the freezing point? Constants can be found here.
Constants for freezing-point depression and boiling-point
elevation calculations at 1 atm:
Solvent
Formula
Kf value*
(°C/m)
Normal freezing
point (°C)
Kb value
(°C/m)
Normal boiling
point
(°C)
water
H2O
1.86
0.00
0.512
100.00
benzene
C6H6
5.12
5.49
2.53
80.1
cyclohexane
C6H12
20.8
6.59
2.92
80.7
ethanol
C2H6O
1.99
–117.3
1.22
78.4
carbon
tetrachloride
CCl4
29.8
–22.9
5.03
76.8
camphor
C10H16O...

What is the final percentage strength (w/w) of a product made by
combining 30 grams of a 50% powder with 20 grams of a 10% powder
and 50 grams of lactose (a diluent with 0% active ingredient)?
Enter your answer as a number with the appropriate
units.
QUESTION 2
When using the method of alligation, active ingredient should be
set to a strength of _____%.
QUESTION 3
How many milliliters of a 1% (w/v) stock solution of a drug
should...

An ophthalmic solution contains tafluprost, 0.0015% w/v,
available in 0.3 mL pouches for single use.
Calculate
(a) the quantity of tafluprost, in micrograms, in each
pouch
b) the number of single-dose pouches that the
manufacturer may prepare from each 1 g of drug.

1) A solution of 1.01 g of benzoic acid in 8.02 g of lauric acid
had a freezing point of 38.9 °C. What is the molar mass of benzoic
acid? The freezing point of lauric acid is 44.0 °C and Kf is 3.60
°C.kg/mol.
2) Calculate the osmotic pressure of a 0.150 M aqueous solution
of caalcium chloride at 25°C.

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