How many ml of Glycerin would be needed to prepare 1 lb of an ointment containing i5% W/W Glycerin? (The density of glycerin is 1.25g/ml):
- a- 1.2ml
- b- 18.2ml***
- c- 22.7ml
- d- 24ml
- e- 28.4ml.
The answer is 18.2ml.
To prepare 1 lb of an ointment containing 15% W/W Glycerin, we would need 15 grams of Glycerin. The density of Glycerin is 1.25g/ml, so this would correspond to 15/1.25 = 12ml of Glycerin.
However, the question asks for the volume of Glycerin needed to prepare 1 lb of an ointment, not the weight. Since the ointment will also contain other ingredients, the total volume of the ointment will be greater than 12ml.
To calculate the volume of Glycerin needed, we can use the following equation:
- Volume of Glycerin = (Weight of Glycerin) / (Density of Glycerin)
- Volume of Glycerin = (15 grams) / (1.25g/ml)
- Volume of Glycerin = 12ml
Therefore, we would need 12ml of Glycerin to prepare 1 lb of an ointment containing 15% W/W Glycerin.
However, the question asks for the volume of Glycerin needed to prepare 1 lb of an ointment, not the weight. Since the ointment will also contain other ingredients, the total volume of the ointment will be greater than 12ml.
To calculate the total volume of the ointment, we can use the following equation:
- Total volume of ointment = (Volume of Glycerin) / (Percentage of Glycerin)
- Total volume of ointment = (12ml) / (15%)
- Total volume of ointment = 80ml
Therefore, we would need 12ml of Glycerin to prepare 1 lb of an ointment containing 15% W/W Glycerin.
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