Measurement and System Units/ SG / Pycnometer
How do you calculate LWQ?
(sensitivity/%error tolerated) x 100%
An injection contains 5 mg of drug in each 10ml vial, if the dose of the drug for a patient is determined to be 150µg. How many milliliters should be administered?
0.3 mL
1 foot = ? meters
0.305 meters
A 50 ml pycnometer if found to weigh 120 g when empty, 171 g when filled with water, and 160 g when filled with an un known liquid. Calculate the specific Gravity of the unknown weight?
0.784
If 27.8 mL of oil weighs 26.2 g, what is the specific gravity of the oil?
0.942
2.2 lbs = how many kg?
1 kg
1 cc = ___ mL
1 mL
A pycnometer when filled with water weighs 23.56 g; when filled with an oil weighs 24.72 g. Calculate the specific gravity of liquid if weight of the empty pycnometer is 12.06 g?
12.66/11.50 = 1.10
An oral suspension contains 1.5g of medications in a pint. Calculate the quantity of medication , in milligrams, present in each 5ml dose?
15.86mg/5ml dose
What is the range of a pycnometer?
1mL to 50mL
1 inch = ? cm
2.54 cm
If sensitivity requirement equals 10 and the % error is 5%, what is the LWQ?
200
The dose of a drug is 0.5 mg/kg of body weight/day. What is the equivalent dose in µg/Ib/day?
227 ug/lb/day
A patient is determined to have a total cholesterol level of 240mg/dl. What is the equivalent in mg/100ml?
240mg/100ml
1 oz = ? grams
28.35 grams
1 fl oz = ? mL
29.57 mL
What is the weight, in grams, of 3620 ml of alcohol with a SG of 0.82?
2968.4
What is the volume, in milliliters, of 492g of nitric acid with a specific gravity of 1.40?
351mL
What is the volume, in pints, of 50 Ib of glycerin having a SG of 1.25?
38.39 pints
What is the volume, in milliliters, if 1 Ib of methyl salicylate with a specific gravity of 1.185?
454ml/1.185 = 383.1
1 tsp = ? mL
5 mL
What is the max %error?
5%
If a pint of a certain liquid weighs 601 g, what is the SG of the liquid?
601g/473g = 1.27
What is determined from the bulk volume and the weight of a dry powder?
Bulk Density
A prescription calls for 0.2 ml of clove oil, Using 5 ml graduate calibrated in units of 0.5ml, how would you obtain the required amount of the clove oil using the aliquot method and alcohol the diluent?
For every 0.5mL, there will be 0.2 mL clove oil and 0.3mL alcohol diluent.
If the minimum weighable quantity is 120 milligrams, show how you can weigh 5 mg of a drug using this scale.? Use the LWQ of 120mg from the previous example.
For every 120 mg aliquot, there will be 5mg drug and 115mg diluent.
A torsion prescription balance has a sensitivity requirement of 6.5milligrams, Explain how you would weigh 15 milligrams of atropine sulfate with an accuracy of ± 5% using lactose as the diluent?
For every 130LWQ, there will be 15mg of atropine sulfate and 115mg of lactose diluent.
If specific gravity is greater than 1, it is?
Heavier than water
What is the standard for gases?
Hydrogen
If specific gravity is less than 1, it is?
Lighter than water
For clinical application of SG, if a patient has an SG of 1.58 when the normal SG value of urine is 1.02 to 1.28, what does that mean?
Means the urine is concentrated. If the SG was <1.02, then the urine would've been diluted
What is the amount of weight required to get a one division shift on the scale?
Sensitivity Requirement
(Weight of substance/weight of equal volume of water) = ?
Specific Gravity
What is a ratio, expressed decimally, of the weight of a substance to the weight of an equal volume of a substance chosen as a standard, both substances at the same temperature?
Specific Gravity
What is employed when a pharmacist wishes to convert the weight of an ingredient or preparation to volume or vice versa?
Specific Gravity
What is determined from the material itself, exclusive of the voids and intra-particle pores larger than molecular or atomic dimensions in the crystal lattices?
True Density
What is used as the standard for the specific gravities of liquid and solids?
Water
If 54.96ml of an oil weighs 52.78, what is the specific gravity of the oil?
(52.78g)/(54.96g) = 0.9603
