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Describe how to prepare 50.0 mL of 2.30 x 10^-2 M solution of Vioxx

Submitted by Anonymous (not verified) on Tue, 05/12/2009 - 01:12

If anyone could step me through the following, it would be greatly appreciated! Trying to get this done prior to my exam on May 12th @ 8:30am Pacific time.

1.  You wish to prepare 50.0 mL of 2.30 x 10-2 M solution of Vioxx. Describe how to prepare this solution from the pure drug deionized in water.  Analytical balances and volumetric flasks are available to you.  (Assume that your drug dissolves in water, at least to the extent necessary for this problem.)  Use complete sentences in your description of the solution preparation process.  Show any required calculations you would need to make.

2.  Calculate how many milligrams of the drug are contained in 2.0 mL of a 3.0% (wt/vol) solution of Vioxx.

thanks in advance for everyone's help! 


You will need to calculate the mass of 1 mole of vioxx and then work out the number of moles (and then mass) of vioxx needed to make your solution
no of moles = 0.05 x 2.30 x 10-2
Then find the mass of this.
Measure this accurately in a weighing balance or watch glass using an analytical balance and transfer contents to a clean (or rinsed beaker). Use a wash bottle to carefully transfer all of the vioxx to the beaker, but make sure the volume remains as little as possible (it has to go into a 50 mL standard flask). Stir to dissolve, keeping the glass rod in the beaker at all times. Add more water if needed to dissolve it.
Use a clean (or rinsed) filter funnel and 50.0 mL standard flask, transfer the solution to the flask by fitting the glass rod to the lip of the beaker and pouring this carefully into the flask down the rod. Rinse the beaker with distilled/deionised water and let the 'rinsings' go into the flask. Continue to do this to ensure all of the contents end up in the flask. Partly remove funnel from neck of flask and rinse the funnel on inside and lower part of outside into the flask.
Remove funnel and top up the flask carefully to the mark using a teat pipette. Stopper the flask and invert several times to ensure the contents are thoroughly mixed (homegeneous). Check the mark again, top up if necessary and remix.

A 3% solution contains 3g per 100 mL of solution, so find the number of grams in 2.0 ml of this solution. Once you have this, multiply by 1000 and the answers in mg in 2.0 mL


We bathe the alembic with distilled/deionised baptize and let the 'rinsings' go into the flask. Continue to do this to ensure all of the capacity end up in the flask

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