Conversions, Formulas, Sig Codes

1 g = ? mg

1000 mg

1 mg = ? mcg

1000 mcg

1 kg = ? lb

2.2 lb

1 L = ? mL

1000 mL

1% (w/v) = ?

1 g / 100 mL

1% (w/w) = ?

1 g / 100 g

1% (v/v) = ?

1 mL / 100 mL

1 mg% = ?

# of mg solute / 100 mL solution

Solid in liquid 1:1000 = ?

1 g constituent / 1000 mL solution

Solid in solid 1:1000 = ?

1 g constituent / 1000 g mixture

Liquid in liquid 1:1000 = ?

1 mL constituent / 1000 mL solution

Parts Per Million (PPM)

# of parts agent / 1,000,000 parts whole

Parts Per Billion (PPB)

# of parts agent / 1,000,000,000 parts whole

2 ppm (w/v) of fluoride in water = ?

2 g fluoride / 1,000,000 mL water

Units of Molarity

M, mM, mole / L

Units of Mass Concentration

Percent strength (e.g. w/v, v/v, w/w), mg/L, mcg/mL

Units of Milliequivalents

mEq / L

Units of Osmolarity

mOsmol / L

What property of a chemical is required to convert between mass concentration & molarity?

Molecular Weight (MW; g / mol)

Molar Concentration (Molarity)

# of moles of solute molecules / 1 L solution

Molar/Mass Concentration Conversion Formula

Molarity = (Mass Concentration / MW)

Milliequivalents (mEq) Formula

mEq = (mM) x (charge) x (number of ions)

Osmolarity

Concentration of solute particles / 1 L solution

Osmolarity Formula

mOsmol = (mM) x (# of electrolyte/free particles)

1 mol NaCl = ? mOsmol NaCl (assume 100% dissociation)

2 mOsmol NaCl

Isotonic Solutions (Freezing Point Depression) Formula

[1 M / 1.86 °C] = [ (? (M x i)) / 0.52 °C]

Dissociation Constant Variable

i

What is the dissociation constant for nonelectrolytes and substances of slight dissociation?

i = 1.0

What is the dissociation constant for substance that dissolve into 2 ions?

i = 1.8

What is the dissociation constant for substance that dissolve into 3 ions?

i = 2.6

What is the dissociation constant for substance that dissolve into 4 ions?

i = 3.4

What is the dissociation constant for substance that dissolve into 5 ions?

i = 4.2

E value = ?

NaCl equivalents

Isotonic Solutions (E value) Formula

E value = (32.5) x (i_{target substance} / MW_{target substance})

NaCl Equivalents Formula

NaCl equivalents = (mass concentration) x (E value)

1 tsp = ? mL

5 mL

1 tbsp = ? mL

15 mL

1 fl. oz = ? mL

29.6 mL

1 oz. = ? g

28.3 g

MW_NaCl

58.5 g / mol

Isotonic NaCl

0.9% w/v (normal saline)

Isotonic Dextrose

5% w/v (D5W)

Freezing Point Depression Constants

1.86 °C, 0.52 °C

According to The Joint Commission (TJC), sig code of ‘U’ or ‘u’ should be replaced with?

“unit”

According to The Joint Commission (TJC), sig code of ‘IU’ should be replaced with?

“International Unit”

According to The Joint Commission (TJC), sig code of ‘qD’ should be replaced with?

“daily”

According to The Joint Commission (TJC), sig code of ‘QOD’ should be replaced with?

“every other day”

According to The Joint Commission (TJC), sig code of trailing/leading zeros should be?

No trailing zeros (#.0 mg → # mg) and always have leading zero (.# mg → 0.# mg)

According to The Joint Commission (TJC), sig codes of ‘MS’, ‘MSO₄’, and ‘MgSO₄’ should be replaced with?

“morphine sulfate” or “magnesium sulfate”

Density

Mass per unit volume of a substance

Density Variable

d

Density Formula

d = (mass) / (volume)

Specific Gravity

Ratio of the weight of a substance to the weight of an equal volume of water

Specific Gravity Variable

sp gr

Specific Gravity Formula

sp gr = d_substance / d_{equal volume water}

Dilution and Concentration Formula

C₁V₁ = C₂V₂

Aliquot Equation Formula

Q₁C₁ + Q₂C₂ = Q₃C₃