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Question 1 of 6
A preparation calls for 350 ml of 80 % Ethanol. What volume of Ethanol (96 per cent) BP do you need for the preparation? Answer to 1 decimal place.
millilitres
96.3
290.8 ml Ethanol (96 per cent) BP to 350 ml Water
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Question 2 of 6
How many grams of Formaldehyde Solution BP (34-38%, density 1.08 g/ml) are needed to prepare 600 ml of a 8 % solution of Formaldehyde?
-
Find the weight of 600 ml of the 8 % W/W solution of Formaldehyde.
Formaldehyde Solution BP has a density of about 1.08 g/ml. You can assume that the 8 % solution also has a density of about 1.08 g/ml. Thus 1 ml of the 8 % solution weighs 1.08 g. Thus:
600 ml of the 8 % solution weighs 600 x 1.08 g = 648 g
You need to prepare 648 g of the 8 % solution. -
Find the mass of Formaldehyde Solution BP needed.
The concentration of Formaldehyde Solution BP is 34-38 % giving an average of 36 %. Using the equation: Concentration1 x Quantity1 = Concentration2 x Quantity236 x Quantity1 = 8 x 648Quantity1 = 5184 g = 144 g
36You need 144 grams of Formaldehyde Solution BP.
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Question 3 of 6
An infusion bag has a volume of 500 ml. You need to prepare one infusion bag containing a solution of Potassium Chloride (RMM 74.6) with a concentration of 0.02 millimoles per millilitre. You must prepare the solution from a 15 % (w/v) solution of Potassium Chloride. How many millilitres of the 15 % solution do you need? Answer to 2 decimal places.
- Find the required concentration as a percent weight in volume.
0.02 millimoles per millilitre = 2 millimoles per 100 millilitres
= 0.002 moles per 100 millilitresMass of KCl in 100 ml of solution = Moles x RMM = 0.002 x 74.6 = 0.1492 g
The required concentration is 0.1492 g/100 ml ie 0.1492 % w/v. - Find the volume of 15 % Potassium Chloride needed.
Concentration1 x Quantity1 = Concentration2 x Quantity215 x Quantity1 = 0.1492 x 500Quantity1 = 74.6 ml
15Quantity1 = 4.973 ml = 4.97 ml to 2 dec pl
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Question 4 of 6
A preparation calls for 400 ml of 55 % Ethanol. You only have available 80 % Ethanol. How many millilitres of Ethanol do you need to prepare the 55 % Ethanol?
80
275 ml 80 % Ethanol to 400 ml Water
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Question 5 of 6
A preparation needs 250 ml of 6 % Formalin. You have available Formaldehyde Solution BP 1988 (34-38 %, density 1.08 g/ml). How much Formaldehyde Solution BP 1988 do you need?
- A 6 % solution of Formalin is the same as a 6 % v/v solution of Formaldehyde Solution BP 1988.
-
Find the volume of Formaldehyde Solution needed.
Concentration1 x Quantity1 = Concentration2 x Quantity2Since you are diluting Formaldeyde Solution BP itself, Concentration1 is 100 %.100 x Quantity1 = 6 x 250Quantity1 = 1500 ml
100Quantity1 = 15 mlFormula:
15 ml Formaldehyde Solution BP to 250 ml Water
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Question 6 of 6
The antiseptic Chlorhexidine Gluconate is available commercially as a 20 % w/v solution. Chlorhexidine Gluconate is issued as a 0.4 % solution. How many millilitres of the commercial product do you need to prepare 5 litres of 0.4 % solution?
20
100 ml Chlorhexidine Gluconate (20 %) to 5000 ml Water
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