A pharmacy intern is aked to prepare 3 L of a 30% solution. The pharmacy stocks the active ingredient in 8-ounce bottles of 70% strength. How many bottles will be needed as the source of the active ingredient?

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Chleachleadelacruzviz Chleachleadelacruzviz · Answer 1

Answer:

The number of bottles of active ingredients that would be needed will be approximately 6.

1 ounce = 0.0296 liters

8 ounce = 0.0296 x 8

=0.2368 Liters

This means that each stock bottle is 0.2368 liters.

From dilution equation:

Molarity x volume before dilution = molarity x volume after dilution

Before dilution: molarity = 70% w/v, volume = ?

After dilution: molarity = 30% w/v, volume = 3 L

volume before dilution = 30 x 3/70

= 1.286 L

Thus, 1.286 liters of the stock would be needed. Each bottle of the stock is 0.2368 liters. Therefore:

1.286/0.2368

= 5.43

Thus, the number of bottles that would be needed is approximately 6.