EXTRA PRACTICE QUESTIONS SET 2

A nurse is given an order to inject lorazepam 3 mg IVP. She has available a 10 mL vial of lorazepam 2 mg/mL and knows that she must dilute the dose prior to IVP administration. According to hospital policy she must dilute the lorazepam to 1 mg/mL with NS. How many milliliters (mL) of NS must she add to the lorazepam dose to dilute it to 1 mg/mL? Please round the final answer to one decimal place, except no trailing zeros.

1.5 mL

Rx Burow's solution 18 mL Hydrocortisone powder 120 mg Calamine lotion qs 240 mL What is the percentage of Burow's solution in the above product? Please round the final answer to one decimal place, except no trailing zeros.

% is in v/v because it is mL over mL (18mL/240mL) * 100 = 7.5% v/v

How many grams (g) of dextrose are required to make 1 liter of a 12.5%w/v solution? Please round the final answer to the nearest whole number.

125 g

What is the weight in grams (g) of one liter of chloroform having a density of 1.48 g/mL? Please round the final answer to the nearest whole number.

1480

You receive a prescription to compound 5 oz. of 5%w/w lidocaine HCl cream. You have available pure lidocaine HCl powder and 3%w/w lidocaine HCl cream. (1 apoth ounce = 31.1g) How many grams (g) of 3%w/w lidocaine HCl cream do you need to compound the prescription above? Please round the final answer to three decimal places, except no trailing zeros.

152.294 g

What is the v/v% of alcohol in the formulation below? Please round the final answer to the nearest whole number. Rx 50% v/v alcohol 500 mL 70% v/v alcohol 500 mL Purified water qs ad 2000 mL

30 v/v%

Rx Salicylic acid powder 300 mg Ppt sulfur 600 mg Petrolatum qs 30 g How many grams (g) of petrolatum are needed to make 3 ounces of the above compound? Please round the final answer to three decimal places, except no trailing zeros. (1 apoth ounce = 31.1g)

300mg = 0.3g; 600mg = 0.6g 30g (Total) - 0.3g(Sal.acid pwd) - 0.6g(Ppt sulfur) = 29.1g(Petrolatum) Set up proportion of (petrolatum/total): 3 ounces x 31.1g/ounce = 93.3 grams total (29.1g/30g) = (x/93.3g); x = 90.501g

How many grams (g) of white petrolatum should be added to 11.25 g of triamcinolone acetonide 0.1% ointment to make a 0.025% ointment? Please round your final answer to three decimal places, except no trailing zeros.

33.75 g

Rx Codeine phosphate 0.015 g Aspirin 0.3 g Disp. #60 caps Sig. ii q 4-6 h prn How many milligrams (mg) of codeine phosphate will the patient receive in each dose? Please round the final answer to the nearest whole number.

The amount listed is per capsule. 1 dose = 2 caps (see sig) 0.015g = 15mg (15mg/cap)(2cap/dose) = 30mg

Rx Codeine phosphate 0.015 g Aspirin 0.3 g Disp. #60 caps Sig. ii q 4-6 h prn What is the maximum amount of aspirin in grams (g) the patient could take per day? Please round the final answer to one decimal place, except no trailing zeros.

The amount listed is per capsule. The maximum the patient could take is every 4 hours or 6 doses/day. Again 1 dose = 2 caps (see sig) (0.3g/cap)x 2 caps/dose x 6 doses/day= 3.6g

A pharmacist dissolves 1g of drug "CD489" in 8 mL of alcohol. What is the %w/w of the solution? Please round the final answer to one decimal place, except no trailing zeros. (sp gr alcohol=0.816; sp gr solution=0.9)

Volume x SG = Weight 8mL alcohol x 0.816 = 6.528g alcohol 1g/(1g + 6.528g) x 100 = 13.2837407 or 13.3%w/w In this case you want to use alcohol's SG because you are given the amount of alcohol (not the amount of the final solution).

The tested level of ammonia in drinking water was determined to be 1.5 ppm. How many grams (g) of ammonia are present in 20 gallons of water? Please round your final answer to three decimal places, except no trailing zeros. (One gallon = 3785 mL)

0.114 g

How many grams (g) of potassium permanganate are needed to make the below Rx? Please round your answer to three decimal places, except no trailing zeros. (One quart = 946 mL) Rx Potassium permanganate 1:7500 Disp. 1 quart Sig. 15 mL in one pint and soak qday

0.126 g

Rx Phenobarbital Elixir 45 mL (15%v/v alcohol) Belladonna tincture 25 mL (65%v/v alcohol) Aromatic elixir 60 mL (22%v/v alcohol) Purified water qs 240 mL What is the final %v/v of alcohol in the above prescription? Please round the final answer to the nearest whole number.

0.15 x 45mL = 6.75mL 0.65 x 25mL = 16.25mL 0.22 x 60 mL = 13.2mL = 36.2mL 36.2mL/240mL total x 100 = 15.083333 = 15%v/v

A patient's blood glucose level is measured to be 284 mg%. Express the amount of glucose in the following concentrations. Please round final answers to two decimal places, except no trailing zeros. Calculate w/v%

0.28 %w/v

How many grams (g) of pure coal tar should be added to 15 grams of 1% coal tar ointment to obtain a 5% coal tar ointment? Please round your final answer to three decimal places, except no trailing zeros. (Note: Pure coal tar = 100%)

0.632 g

What is the %w/w of coal tar in a preparation made by adding 10g pure coal tar to 100 g of 5%w/w coal tar ointment? Please round the final answer to one decimal place, except no trailing zeros.

1 x 10g = 10g 0.05 x 100g = 5g = 15g coal tar 15g coal tar/110g total product x 100 = 13.63636363 = 13.6%w/w The 10g of coal tar is 100% coal tar. The above work is shown solving the problem using alligation medial. There is another way to solve this problem shown below. (5g+10g) * 100 = 13.6%w/w 100g+10

A patient's blood glucose level was determined to be 310 mg%. How many grams (g) of glucose are found in one pint of the patient's blood? Please round your final answer to two decimal places, except no trailing zeros. (One pint = 473 mL)

1.47 g

What is the weight in kilograms (kg) of 3 pints of lactic acid solution? The specific gravity of lactic acid is 1.21. (1 pint = 473 mL) Please round the final answer to three decimal places, except no trailing zeros.

1.717 kg

How many grams (g) of 10%w/w salicylic acid ointment must be mixed with 25 grams of 2%w/w salicylic acid ointment in order to prepare 8%w/w salicylic acid ointment? Please round the final answer to three decimal places, except no trailing zeros.

10% 6 parts of 10% (x) 8% 2% 2 parts of 2% (25g) 8 parts of 8% (x+25g) 2parts/6parts = 25g/x x= 75g This is an alligation alternate problem since you know the % of all the parts of the problem, but you do not know how much of each product to use. It can also be solved algebraically. You can also solve using the total grams as the denominator, but you need to remember that the 25g is from the 2% ointment and is not the total amount. The proportion would need to be 6parts/8parts = (x/(x+25g)). You will reach the same answer 75g. Our balances measure in grams and can measure to three decimal places however in this case since there are trailing zeros we do NOT include them in our answer.

How many milliliters (mL) of 95%w/w sulfuric acid having a sp. gr. of 1.82 should be used in preparing 2 liters of 10% w/v sulfuric acid? Please round your final answer to one decimal place, except no trailing zeros.

115.7 mL

If 143 grams of dextrose are dissolved in 1000 mL of water, what is the % strength (w/w) of the solution? Please round your final answer to one decimal place, except no trailing zeros.

12.5 w/w%

A concentrated sodium chloride solution is supplied as a 14.6%w/v solution with a specific gravity of 1.1. What is the w/w% of the solution? Please round the final answer to two decimal places, except no trailing zeros.

13.27 w/w%

A patient's blood glucose level is measured to be 284 mg%. Express the amount of glucose in the following concentrations. Please round final answers to two decimal places, except no trailing zeros. Calculate ratio strength

1:352.11

Convert 0.25%w/w to a ratio strength. Please round the final answer to the nearest whole number.

1:400

A pharmacist receives a prescription for bacitracin 10,000 units per one liter in NS, dispense 500 mL. This solution will be used for irrigation. How many milligrams (mg) of bacitracin must be used to prepare this prescription? Please round the final answer to the nearest whole number. (1 mg = 50 units)

1L = 1000mL (10,000units/1000mL) = (x/500mL) x = 5000 units 5000units(1mg/50 units) = 100 mg

If 8 grams of "Drug M" are added to 240 mL of Simple Syrup (specific gravity of Simple Syrup 1.31), what is the % strength (w/w) of the solution? Please round the final answer to one decimal place, except no trailing zeros.

2.5 %w/w

What is the specific gravity of a liquid if 2.5 liters of the liquid weighs 3.2 kg? Please round the final answer to two decimal places, except no trailing zeros.

2.5L = 2500mL 3.2kg = 3200g 3200g/2500mL = 1.28g/mL Specific gravity is mass of a substance divided by mass of an equal volume of water So for 1mL 1.28 g of liquid/ 1 g of water = 1.28 (Note: no units) Units are not included in the answer since SG has no units.

A patient's blood glucose level is measured to be 284 mg%. Express the amount of glucose in the following concentrations. Please round final answers to two decimal places, except no trailing zeros. Calculate mg/mL

2.84 mg/mL

How many grams (g) each of 5% sulfur ointment and 20% sulfur ointment must be mixed in order to get 60 grams of 15% sulfur ointment? Please round your final answers to three decimal places, except no trailing zeros.

20 g of 5% sulfur ointment 40 g of 20% sulfur ointment

How many milliliters (mL) of a 1:50 w/v stock solution of a chemical should be used to prepare one liter of a 1:2000 w/v solution? Please round the final answer to the nearest whole number.

25 mL

One gallon of a lotion contains 946 mL of benzyl benzoate. Calculate the % of benzyl benzoate in the lotion. Please round the final answer to the nearest whole number. (1 gallon = 3785 mL)

25 v/v%

A patient's blood glucose level is measured to be 284 mg%. Express the amount of glucose in the following concentrations. Please round final answers to two decimal places, except no trailing zeros. Calculate ppm

2840 ppm

What is the volume in milliliters (mL) of 2 oz. (avoir) of mineral oil? Please round the final answer to two decimal places, except no trailing zeros. (specific gravity mineral oil = 0.8825, 1 avoir. oz. = 28.35g)

2oz avoir (28.35g/oz) = 56.7g Weight/SG = Volume; 56.7/0.8825 = 64.24929mL = 64.25mL Need to convert to metric system to solve using SG.

A prescription calls for 5%w/w hydrocortisone ointment. How many grams (g) of hydrocortisone powder should be added to 2%w/w hydrocortisone ointment in order to make 2 oz. of the 5%w/w ointment? ? Please round the final answer to three decimal places, except no trailing zeros.(1 apoth ounce = 31.1g)

2oz x 31.1g/oz = 62.2g 100% 3 parts of 100% (x) 5% 2% 95 parts of 2% (y) 98 parts of 5% (62.2g) 3 parts/98 parts = x/62.2g x = 1.904081633g or 1.904g

You receive a prescription to compound 5 oz. of 5%w/w lidocaine HCl cream. You have available pure lidocaine HCl powder and 3%w/w lidocaine HCl cream. (1 apoth ounce = 31.1g) How many grams (g) of lidocaine HCl powder do you need to compound the prescription above? Please round the final answer to three decimal places, except no trailing zeros.

3.206 g

A pharmacist receives a prescription for 4 oz. of 7%w/w zinc oxide ointment. How many grams (g) of 2.5%w/w zinc oxide ointment must be mixed with 10%w/w zinc oxide to prepare this prescription? Please round the final answer to three decimal places, except no trailing zeros. (1 apoth ounce = 31.1g)

4 oz x 31.1g/oz = 124.4g 10 % 4.5 parts of 10% (y) 7% 2.5% 3 parts of 2.5% (x) 7.5 parts of 7% (124.4g) Question 21: 3 parts/7.5parts = x/ 124.4g x= 49.76g of 2.5% Question 22: 4.5 parts/7.5 parts = y/124.4g y= 74.64g of 10% Check using Alligation Medial 0.1 x 74.64g = 7.464g 0.025 x 49.76 = 1.244g = 8.708g 8.708g/124.4g total x 100 = 7%

How many grams (g) of 10%w/w zinc oxide ointment must be mixed with 2.5%w/w zinc oxide to prepare the prescription in question 21? Please round the final answer to three decimal places, except no trailing zeros.

4.5 parts/7.5 parts = y/124.4g y= 74.64g of 10% Check using Alligation Medial 0.1 x 74.64g = 7.464g 0.025 x 49.76 = 1.244g = 8.708g 8.708g/124.4g total x 100 = 7% ANSWER: 74.64

What is the weight in grams (g) of 2 f℥ of castor oil with a specific gravity of 0.96? Please round your final answer to two decimal places, except no trailing zeros. (1 f℥ = 29.57mL)

56.77

A pharmacist dissolves 1.95 grams of drug in enough water to make 30 mL of solution. What is the w/v% of the drug in solution? Please round your final answer to one decimal place, except no trailing zeros.

6.5 w/v%

A pharmacist dissolves 1.2 grams of drug in 20 mL of alcohol (sp. gr. 0.816), what is the % strength (w/w) of drug in solution? Please round your final answer to one decimal place, except no trailing zeros.

6.8 w/w%

How many grams (g) of codeine phosphate are found in 6 fluid ounces of codeine elixir with a concentration of 12 mg/5 mL? Please round the final answer to three decimal places, except no trailing zeros. (1 fluid ounce = 29.57 mL)

6floz (29.57mL/1floz) = 177.42mL Proportion with concentration: (12mg/5mL) = (x/177.42mL); x = 425.808mg Convert to g: 425.808mg(1g/1000mg) = 0.4258g = 0.426g

How many grams of tannic acid must be dissolved in 240 mL of glycerin (sp. gr. 1.25) to make a 20 % w/w solution? Please round the final answer to the nearest whole number.

75 g

A nurse is given an order to inject promethazine 12.5mg IVP. She has available a 25mg/mL vial of promethazine and knows that she must dilute it to prevent tissue damage and irritation. According to hospital policy she must dilute the promethazine to 1.25mg/mL with NS. How many milliliters (mL) of NS must she add to the promethazine to dilute it to 1.25mg/mL? Please round the final answer to one decimal place, except no trailing zeros.

9.5 mL

How many milliliters (mL) of a 5% w/v solution of menthol in alcohol should be used to obtain the amount of menthol needed in preparing the liquid? Please round your final answer to one decimal place, except no trailing zeros. Rx Menthol Hexachlorophene aa 0.1% Glycerin 10% 70% alcohol qs 480 mL

9.6 mL

A patient's blood glucose level is measured to be 175mg%. Express the amount of glucose in the following concentrations. Please round the final answers to the nearest whole number. Calculate ratio strength

Convert 175mg% to g/100mL (or another more manageable number). Remember that mg% is (mg/100mL). (175mg/100mL) = (0.175g/100mL) (0.175g/100mL) = (1/x); x = 571.42857mL; translates to 1:571 No units need to be put with ratio strength, it is understood that it is in g and mL.

A patient's blood glucose level is measured to be 175mg%. Express the amount of glucose in the following concentrations. Please round the final answers to the nearest whole number. Calculate ppm

Convert 175mg% to g/100mL (or another more manageable number). Remember that mg% is (mg/100mL). (175mg/100mL) = (0.175g/100mL) (0.175g/100mL) = (x/1,000,000); x = 1750g; translates to 1750ppm

How many milliliters (mL) of water must be added to 1 fl. oz. of 1.5%w/v sodium chloride solution in order to make a 1:400 sodium chloride solution? Please round the final answer to two decimal places, except no trailing zeros. (1 fl. oz. = 29.57mL)

First convert 1:400 to w/v% 1g/400mL = x/100mL x= 0.25% QC=QC (29.57mL)(1.5%w/v) = (x)(0.25%w/v) x = 177.42mL total 177.42mL-29.57mL = 147.85mL (water added)

How many grams (g) of sodium chloride crystals would be needed to make a 250 mL of NS solution? Please round the final answer to three decimal places, except no trailing zeros.

NS = 0.9% w/v NaCl (0.9g/100mL) = (x/250mL) x = 2.25g Remember that w/v percentages are in grams and milliliters. This is set up as a proportion, you can also solve algebraically.

How many milliliters (mL) of water should be added to 40 mL of 50%w/v urea solution in order to prepare a 10%w/v urea solution? Please round the final answer to the nearest whole number.

QC = QC 40mL(50%w/v) = x(10%w/v) x= 200mL total 200mL - 40mL = 160mL (water added) OR 50% 10 parts of 50% (40mL) 10% 0% 40 parts of 0% or water (x) 50 parts of 10% (x + 40mL) 10parts/40parts = 40mL/x x = 160mL

Syrup U.S.P. is a 65%w/w solution of sucrose in water with a specific gravity of 1.3. What is the %w/v of the solution? Please round the final answer to one decimal place, except no trailing zeros.

SG (%w/w) = (%w/v) 1.3(65%w/w) = 84.5%w/v Leave the % in whole numbers (do not convert to decimal), then your answer will be in whole numbers. Make sure you know how to convert back and forth between %w/w and %w/v.

The normal dose of a drug is 15 mg/kg BID. How many milliliters (mL) of a 2.5% drug solution are needed to supply a 56 lb. patient with a week's supply of medication? Please round the final answer to the nearest whole number.

Solve for kg: 56lb/2.2lb/kg = 25.45454545 kg Find out how many g/week (need to convert mg, doses, and days) 25.45454545kg(15mg/kg)(1g/1000mg)(2 doses/day)(7 days/week) = 5.345454545g/week Set up proportion with 2.5%: (5.345454545g/x) = (2.5g/100mL) x = 213.818181818mL= 214 mL

Rx Triamcinolone ac. 1%(w/w) cr. 5% Velvachol qs 1 oz. Calculate the percentage strength of triamcinolone acetonide in the above prescription. Please round the final answer to two decimal places, except no trailing zeros. (1 apoth ounce = 31.1g)

The 5% represents 5% of the final compounded product. 1oz (apoth) = 31.1g 31.1g(0.05) = 1.555g of the compound is Triamcinolone acetonide 1% Set up proportion to find amount of pure triamcinolone: (1g/100g) = (x/1.555g); x = 0.01555g is pure triamcinolone acetonide Find % triamcinolone acetonide in final product: 0.01555g/31.1g * 100 = 0.05%w/w It is %w/w because there are grams over grams.

Rx Sodium fluoride powder 10 g Kaolin 10 g Glycerin 10 g M. ft. paste Sig: apply to teeth bid How many milliliters (mL) of glycerin are needed to fill the above prescription? Please round the final answer to the nearest whole number. (specific gravity glycerin = 1.249)

Weight/SG = Volume 10g/1.249 = 8.006405mL = 8 mL M. ft. paste = Mix to make paste