● Stoichiometry is the use of quantitative relationships between substances that are involved
in chemical reactions which determine the amounts of the reactants or the products (Bauer, Birk, &
Marks, 2019).
S
...
● Stoichiometry is the use of quantitative relationships between substances that are involved
in chemical reactions which determine the amounts of the reactants or the products (Bauer, Birk, &
Marks, 2019).
Stoichiometry - the process of determining the amounts of substances in a chemical reaction (Bauer, Birk, & Marks, 2019).
● It is used to relate the reactants and products by using
calculations and balanced equations (Bauer, Birk, & Marks, 2019).
● By knowing the amount of a reactant or a product, it is easier to determine the amount of another reactant or product in the same reaction and balance the equation (Bauer, Birk, & Marks, 2019).
● Stoichiometry calculations deal with the mass or volumes of products and reactants. ● To solve stoichiometry problems it is important to master balancing equations, converting between grams and moles, calculating molar mass, and calculating mole ratios.
● Stoichiometry is the study of mass relations, where one or more substances undergo a physical change or a chemical change.
● After doing the calculations and conversions the equation must be balanced.
● After the equation is balanced, it is important to determine the mole relationship between the reactants and products in the chemical equation (Bauer, Birk, & Marks, 2019).
Stoichimetry Tutorial
● Steps to balancing Stoichiometry:
○ Identify each element in the equation. The number of atoms for each element
must be the same on each side to be balanced.
○ The net charge must be the same on each side of the equation.
○ Start with the elements in one compound and change the number of the coefficient until the atoms are equal on each side.
○ Once you balance one element, then you must balance the rest before checking your work (Bauer, Birk, & Marks, 2019).
● Unbalanced:
● Balanced:
❖ When solving a mass-mass problem it is important to follow certain steps.
❖ The main steps in a mass-mass conversion are:
➢ Balancing the chemical equation by applying the the Law of Conservation of Mass. In a balanced equation you have to have the same number of each type of atom on both the reactants side and the products side.
➢ Then, it is important to convert the mass values into moles by using the molar mass. ➢ Next, use the molar proportion to determine the unknown quantities of moles. This is done by setting two molar ratios equal to each other, with the unknown value being the only value to solve.
➢ Finally, using the molar mass of that substance, the mole value must be converted into a mass (Bauer, Birk, & Marks, 2019).
(“Solving Stoichiometry Problem”)
(“Solving Stoichiometry Problem”)
(“Solving Stoichiometry Problem”)
How many liters of SO2 will be produced from 26.9L O2?
(“Solving Stoichiometry Problem”)
● One major responsibility in nursing is medication administration. ● Ensuring that the correct dosage is given to the right patient requires knowledge of dosage calculations.
● With the use of dimensional analysis we can quickly and accurately calculate the appropriate amount of drug to be administered to ensure patient safety.
● Drugs that are prescribed or ordered, aren’t always prepared in the
needed units of measurement.
● Knowledge of how to convert a liquid from milliliters to teaspoons, or a medication from grams to micrograms is needed when preparing to administer medications safely.
● The International System of Units (SI units) in the metric system refer to a dimension, such as weight (or mass), volume, and length. The metric system is logical, precise, and easy to work with because it’s a standardized decimal measurement system using multiples (powers) of 10, similar to our monetary structure, which is also based on a decimal structure (Mulholland and Turner, 2015).
● Examples of metric units of measurement include kilogram (kg), microgram (mcg), milligram (mg), gram (g), liter (L), and meter (m).
● The metric units of measurement are used by chemists, nurses and healthcare
workers in most countries.
● It is a simple organized system for setting up problems. ● It reduces dependence on memory.
Dimensional analysis (DA) is a systematic mathematical method derived from the sciences that is used to solve equations with an emphasis on units of measurement to set up the equation (Mulholland & Turner, 2015 p. 50).
Advantages to using the DA method to solve medication dosage problems include:
● This method may be used for all medication dosage problems.
● All of the calculations for a dosage can be entered into a single equation.
● It allows the nurse to easily identify an incorrect setup before calculations are carried out; which is a key factor in efficiency and reduction of errors.
-This method requires three elements: (1) desired answer units, (2) given quantity and units to
convert, and (3) conversion factors.
Step by Step Tutorial
Nurses use dimensional analysis while at
work almost every day!
Nurses use this method because it is a quick and easy way to solve dosage calculations for medication administration!
When calculating the correct doses it it imperative that nurses ensure this is correct. By becoming skilled in dimensional analysis, it allows for nurses to ensure patient safety!
(Toney-Butler, 2019)
Nurses also use stoichiometry in
the workplace!
It is similar in comparison to Dimensional analysis. Just like dimensional analysis, stoichiometry is used to set up calculations. This is key when solving for the correct dosage for a patient.
Using dimensional analysis and Stoichiometry
The MD orders 5 grams of Lactulose by mouth twice daily. The pharmacy provides you with 40 grams per 30 mL. How many mL will you administer per dose?
(Khan Academy, 2020).
(Registered Nurse RN, 2016).
Bauer, R. C., Birk, J. P., & Marks, P. (2019). Introduction to chemistry. New York, NY: McGraw-Hill Education.
Khan Academy. (2020). Stoichiometry: stoichiometric ratio examples (article). Retrieved from https://www.khanacademy.org/science/chemistry/chemical-reactions-stoichiome/stoichiometry-ideal/a/stoichiometry
Mulholland, J. M., & Turner, S. J. (2015). The nurse, the math, the meds: drug calculations using dimensional analysis. St. Louis, MO: Elsevier/Mosby.
Registered Nurse RN. (2016, June 10). How to Solve Oral Drug Dosage Calculations in Nursing School. Retrieved from https://www.registerednursern.com/how-to-solve-oral-drug-dosage-calculations-in-nursing-school/
Solving Stoichiometry Problem. (n.d.). Retrieved February 23, 2020, from http://www.csun.edu/~psk17793/G Chemistry/solving_stoichiometry_problems.htm
Toney-Butler, T. J. (2019, July 30). Dose Calculation (Dimensional Analysis, Factor-Label Method). Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK430724/
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