Question

True or false?

1) A 50% solution would contain 5000 mg/mL.

2) A solution with 500 mg of drug would be more concentrated than an equal volume solution with 5 g of drug.

3) Half strength saline is 0.45%. Normal saline would have 9 mg/mL of NaCl.

4) You are instructed to dispense 120 mL of lactulose to a patient. You would get a 3 oz. bottle from the storeroom to accomplish this.

5) 10 mcg is equal to 1 x 10^-5 grams.

Answer 1

1) A 50% solution would contain 5000 mg/mL.

False.

First convert 1% solution to mg/mL.

A 1% solution is the same as 1000 milligrams in 100 mL or 10mg/mL

( 1mL= 1CC)

1%= 10 mg/mL

2%= 20 mg/mL

.......

50%=500mg/mL

2) A solution with 500 mg of drug would be more concentrated than an equal volume solution with 5 g of drug.

False

1gm =1000mg

5g =5000mg

5g of drug is more concentrated than 500 mg in equal volume solution.

3) Half strength normal saline is 0.45%

True

Normal saline would have 9 mg/mL of NaCl.

True.

0.9 % normal saline = 9 g/L

1g =1000 mg

1L= 1000mL

1g/L = 1mg /mL

9g/L = 9mg/mL

0.9%=9mg/mL

Half strength = 0.9 ÷ 2=0.45%

= 4.5 g/L=4.5 mg/mL

4) You are instructed to dispense 120 mL of lactulose to a patient. You would get a 3 oz. bottle from the storeroom to accomplish this.

False

1 ounce = 30 mL

1 mL= 1/30 ounce

120 mL= 1/30 ×120 = 4 Ounce

5) 10 mcg is equal to 1 x 10-5 grams.

True

1 mcg = 1× 10 -6 gm

10 mcg = 10×1×10-6

= 1× 10-5 g