CHEM 120 - Week 3 -6.pdf 8/20/2026 CHEM 120 - Week 3 -6.pdf
Michael Heika
OL Lab 3: Stoichiometry: Avogadro’s number and molecular
calculations / Solution Preparation: From salt to solution
Learning Objectives:
· Explain the relationship between mass, molecular weight, and numbers of atoms or
molecules and perform calculations deriving these quantities from one another
· Perform mass-to-mass stoichiometric calculations via conversions to moles
· Identify the limiting and excess reagents in a chemical reaction
· Calculate the theoretical, actual and percent reaction yield
· Define Avogadro’s number and describe the mole quantification of matter
· Explain relationship between mass, molecular weight, and numbers of atoms or
molecules
· Perform conversion and derivations calculations using key molecular quantity
parameters
· Define Avogadro’s number and describe the mole quantification of matter
How many moles of sand grains has the Sahara desert? What is the only equation
you´ll ever need in chemistry? The short stoichiometry simulation will help you answer
those questions! Follow the footsteps of great chemists and learn about key molecular
parameters based on one and only star of chemistry calculations: Avogadro’s Law!
Concept mole and Avogadro’s Law:
Your first mission in this short simulation is to familiarize yourself with the concept of
mole and the way of counting molecules of substances using the one and only
Avogadro’s Law. You will learn how to convert huge numbers of particles into handy
Avogadro’s number, extensively used by all chemists around the world!
Chemical units relationship:
Next, you will explore the relationship between mass, molecular weight, and number of
atoms. This magical equation will enable you to perform derivations of molecular
quantity parameters for various chemical substances. You will feel like Marie Curie
This study source was downloaded by 884789 from cliffsnotes.com on 04-04-2025 16:08:24 GMT -05:00
CHEM 120 - Week 3 -6.pdf
https://www.cliffsnotes.com//study-notes/24744256 CHEM 120 - Week 3 -6.pdf CHEM 120 - Week 3 -6.pdf
,CHEM 120 - Week 3 -6.pdf 8/20/2026 CHEM 120 - Week 3 -6.pdf
analysing chemical dependencies of chemicals in her French laboratory! Part 1:
Complete the Labster lab: Stoichiometric calculations: Identify an unknown compound
using gravimetric analysis.
Glassware and quantitative transfer
Moving on to the second workbench, you will explore and determine what glassware
will be appropriate for you to use. Your lab guide and mentor, Dr. One, will walk you
through the process of preparing the solution. You will have the freedom to use the
equipment as you like, but only by following Dr. One’s instructions will you be successful
in making the right solution. To make sure you can always redo the essential steps of
the process, Dr. One will provide you with a fantastic reset button, so you can try again
if you make a mistake.
Solve the preparation
In the end, only by carefully ensuring that the right amount of water and ammonium
chloride is used can you make the correct solution. Are you prepared for solving how to
perform a Solution Preparation?
Part 1: Complete the Labster Lab: Stoichiometry: Avogadro’s number and
molecular calculations
Complete all activities and answer all questions within the lab and then complete the
questions below:
Purpose: Describe in complete sentences and in your own words, the purpose of this
experiment.
The purpose of this experiment is to deepen our understanding of the fundamental
concepts in chemistry, particularly those related to stoichiometry and the mole concept.
Observations: Record three observations from the simulation.
I. Learn how to use the salt to an H2O solution. We also learned how to
demineralized water does not contain minerals.
II. How and when to utilize certain tools in a labsuch as balancing a scale and a
volumetric flask
III. Learned about the reaction of the stoichiometry and how the number of moles
are formed.
This study source was downloaded by 884789 from cliffsnotes.com on 04-04-2025 16:08:24 GMT -05:00
CHEM 120 - Week 3 -6.pdf
https://www.cliffsnotes.com//study-notes/24744256 CHEM 120 - Week 3 -6.pdf CHEM 120 - Week 3 -6.pdf
,CHEM 120 - Week 3 -6.pdf 8/20/2026 CHEM 120 - Week 3 -6.pdf
1. How do you convert between grams and moles of a specific molecule? Give a specific
example to illustrate.
To convert between grams and moles of a specific molecule, you need to use the molecular
weight of the molecule, which is usually given in grams per mole (g/mol). This value can be
found on the periodic table for individual elements or calculated for molecules by adding up the
atomic weights of all the atoms in the molecule.
To illustrate this with an example, I will use water (H2O):
The molecular weight of water is approximately 18.015 g/mol (1.008 g/mol for Hydrogen and
15.999 g/mol for Oxygen, and since water has 2 Hydrogen atoms and 1 Oxygen atom, we add
(2*1.008) + 15.999).
To convert grams to moles: If we have 36.03 grams of water, we divide this by the molecular
weight of water (18.015 g/mol) to get approximately 2 moles of water.
To convert moles to grams: If we have 2 moles of water, we multiply this by the molecular weight
of water (18.015 g/mol) to get 36.03 grams of water.
2. How do you convert between moles of one substance and moles another substance?
To convert between moles of one substance and moles of another substance, you need to use
the stoichiometric coefficients from the balanced chemical equation of the reaction. These
coefficients tell you the ratio in which the substances react or are produced.
3. Balance the following chemical equation:
Na2CO3(aq) + CaCl2(aq) → CaCO3(s) + NaCl(aq)
Na2CO3(aq) + CaCl2(aq) -> CaCO3(s) + 2NaCl(aq)
4. Use the balanced chemical equation from the last question to solve this situation: You
combine 0.5 moles of Na2CO3 with enough CaCl2 that your compound reacts completely. How
many moles of NaCl would you expect this reaction to produce? Show all work below. If you
are not sure how to complete this problem, please see the video here:
https://care.mediaspace.kaltura.com/playlist/dedicated/254042593/1_aw4f9v30/1_4xqaj516
Mass Na2Co3 = 106g/mol
Mole of Na2CO3 in 5.g = 0.5g/106g/mol
Mole of Na2CO3 in 5g = 0.00472 mol2 mol NaCl
0.00472 mol of Na2CO3 produce 2 X 0.00472 mol of NaCl.
0.00944mol total Mole of NaCl Molar mass of NaCl= 58.44g/mol
Mass of NaCl in 0.00944 mol + (0.00944 mol) (58.44g/mol)
Mass of NaCl produced =0.552g
This study source was downloaded by 884789 from cliffsnotes.com on 04-04-2025 16:08:24 GMT -05:00
CHEM 120 - Week 3 -6.pdf
https://www.cliffsnotes.com//study-notes/24744256 CHEM 120 - Week 3 -6.pdf CHEM 120 - Week 3 -6.pdf
, CHEM 120 - Week 3 -6.pdf 8/20/2026 CHEM 120 - Week 3 -6.pdf
Part 2: Complete the Labster Lab: Solution Preparation: From salt to solution
Complete all activities and answer all questions within the lab and then complete the
questions below:
1. In this lab, you learned how to prepare solutions with a precise concentration.
Where in your nursing career might this skill be needed?
Preparing solutions with precise concentrations is a crucial skill in nursing for several
reasons:
● Medication Administration: Many medications are delivered in a concentrated
form and must be diluted before administration. The concentration must be
accurate to ensure the patient receives the correct dose.
● IV Fluids: Intravenous fluids often contain various solutes like electrolytes or
medications. Nurses must understand concentrations to prepare these fluids
correctly.
● Lab Work: Nurses may need to prepare solutions for certain lab tests. For
example, glucose tolerance tests require a precise concentration of glucose.
2. Which piece of glassware did you use to prepare your solution in this lab and
why?
In this lab a flask was used to prepared the solution and a beaker wasalso used. The
beaker was used to poor the solution and then transferred to the flask to avoid spelling.
The flask also had a long neck to avoid spilling and it is great to use for dilutions
3. Calculate how many grams of NaCl are required to make 100 mL of a 1 M NaCl
solution. Show your work in the space below.
Molar mass of NaCl is 58.44 g/mol
58.44 g of NaCl will be there in 1 M of 1 L NaCl solution.
100 mL 1 M NaCl solution.
(Mass = Molarity x molar mass x volume in liters)
Mass = (1mol/1L) x (58.44 g/mol) x (100L/1000) = 5.844 g
Reflection: Consider what you learned from these simulations. Reflect on three to four
key concepts that you learned in this lab exercise. How could the lessons learned in
this virtual lab relate to a real world situation in the community/world or your future
career as a nurse? Be specific in your answer (this should require 5-10 sentences).
This study source was downloaded by 884789 from cliffsnotes.com on 04-04-2025 16:08:24 GMT -05:00
CHEM 120 - Week 3 -6.pdf
https://www.cliffsnotes.com//study-notes/24744256 CHEM 120 - Week 3 -6.pdf CHEM 120 - Week 3 -6.pdf
Michael Heika
OL Lab 3: Stoichiometry: Avogadro’s number and molecular
calculations / Solution Preparation: From salt to solution
Learning Objectives:
· Explain the relationship between mass, molecular weight, and numbers of atoms or
molecules and perform calculations deriving these quantities from one another
· Perform mass-to-mass stoichiometric calculations via conversions to moles
· Identify the limiting and excess reagents in a chemical reaction
· Calculate the theoretical, actual and percent reaction yield
· Define Avogadro’s number and describe the mole quantification of matter
· Explain relationship between mass, molecular weight, and numbers of atoms or
molecules
· Perform conversion and derivations calculations using key molecular quantity
parameters
· Define Avogadro’s number and describe the mole quantification of matter
How many moles of sand grains has the Sahara desert? What is the only equation
you´ll ever need in chemistry? The short stoichiometry simulation will help you answer
those questions! Follow the footsteps of great chemists and learn about key molecular
parameters based on one and only star of chemistry calculations: Avogadro’s Law!
Concept mole and Avogadro’s Law:
Your first mission in this short simulation is to familiarize yourself with the concept of
mole and the way of counting molecules of substances using the one and only
Avogadro’s Law. You will learn how to convert huge numbers of particles into handy
Avogadro’s number, extensively used by all chemists around the world!
Chemical units relationship:
Next, you will explore the relationship between mass, molecular weight, and number of
atoms. This magical equation will enable you to perform derivations of molecular
quantity parameters for various chemical substances. You will feel like Marie Curie
This study source was downloaded by 884789 from cliffsnotes.com on 04-04-2025 16:08:24 GMT -05:00
CHEM 120 - Week 3 -6.pdf
https://www.cliffsnotes.com//study-notes/24744256 CHEM 120 - Week 3 -6.pdf CHEM 120 - Week 3 -6.pdf
,CHEM 120 - Week 3 -6.pdf 8/20/2026 CHEM 120 - Week 3 -6.pdf
analysing chemical dependencies of chemicals in her French laboratory! Part 1:
Complete the Labster lab: Stoichiometric calculations: Identify an unknown compound
using gravimetric analysis.
Glassware and quantitative transfer
Moving on to the second workbench, you will explore and determine what glassware
will be appropriate for you to use. Your lab guide and mentor, Dr. One, will walk you
through the process of preparing the solution. You will have the freedom to use the
equipment as you like, but only by following Dr. One’s instructions will you be successful
in making the right solution. To make sure you can always redo the essential steps of
the process, Dr. One will provide you with a fantastic reset button, so you can try again
if you make a mistake.
Solve the preparation
In the end, only by carefully ensuring that the right amount of water and ammonium
chloride is used can you make the correct solution. Are you prepared for solving how to
perform a Solution Preparation?
Part 1: Complete the Labster Lab: Stoichiometry: Avogadro’s number and
molecular calculations
Complete all activities and answer all questions within the lab and then complete the
questions below:
Purpose: Describe in complete sentences and in your own words, the purpose of this
experiment.
The purpose of this experiment is to deepen our understanding of the fundamental
concepts in chemistry, particularly those related to stoichiometry and the mole concept.
Observations: Record three observations from the simulation.
I. Learn how to use the salt to an H2O solution. We also learned how to
demineralized water does not contain minerals.
II. How and when to utilize certain tools in a labsuch as balancing a scale and a
volumetric flask
III. Learned about the reaction of the stoichiometry and how the number of moles
are formed.
This study source was downloaded by 884789 from cliffsnotes.com on 04-04-2025 16:08:24 GMT -05:00
CHEM 120 - Week 3 -6.pdf
https://www.cliffsnotes.com//study-notes/24744256 CHEM 120 - Week 3 -6.pdf CHEM 120 - Week 3 -6.pdf
,CHEM 120 - Week 3 -6.pdf 8/20/2026 CHEM 120 - Week 3 -6.pdf
1. How do you convert between grams and moles of a specific molecule? Give a specific
example to illustrate.
To convert between grams and moles of a specific molecule, you need to use the molecular
weight of the molecule, which is usually given in grams per mole (g/mol). This value can be
found on the periodic table for individual elements or calculated for molecules by adding up the
atomic weights of all the atoms in the molecule.
To illustrate this with an example, I will use water (H2O):
The molecular weight of water is approximately 18.015 g/mol (1.008 g/mol for Hydrogen and
15.999 g/mol for Oxygen, and since water has 2 Hydrogen atoms and 1 Oxygen atom, we add
(2*1.008) + 15.999).
To convert grams to moles: If we have 36.03 grams of water, we divide this by the molecular
weight of water (18.015 g/mol) to get approximately 2 moles of water.
To convert moles to grams: If we have 2 moles of water, we multiply this by the molecular weight
of water (18.015 g/mol) to get 36.03 grams of water.
2. How do you convert between moles of one substance and moles another substance?
To convert between moles of one substance and moles of another substance, you need to use
the stoichiometric coefficients from the balanced chemical equation of the reaction. These
coefficients tell you the ratio in which the substances react or are produced.
3. Balance the following chemical equation:
Na2CO3(aq) + CaCl2(aq) → CaCO3(s) + NaCl(aq)
Na2CO3(aq) + CaCl2(aq) -> CaCO3(s) + 2NaCl(aq)
4. Use the balanced chemical equation from the last question to solve this situation: You
combine 0.5 moles of Na2CO3 with enough CaCl2 that your compound reacts completely. How
many moles of NaCl would you expect this reaction to produce? Show all work below. If you
are not sure how to complete this problem, please see the video here:
https://care.mediaspace.kaltura.com/playlist/dedicated/254042593/1_aw4f9v30/1_4xqaj516
Mass Na2Co3 = 106g/mol
Mole of Na2CO3 in 5.g = 0.5g/106g/mol
Mole of Na2CO3 in 5g = 0.00472 mol2 mol NaCl
0.00472 mol of Na2CO3 produce 2 X 0.00472 mol of NaCl.
0.00944mol total Mole of NaCl Molar mass of NaCl= 58.44g/mol
Mass of NaCl in 0.00944 mol + (0.00944 mol) (58.44g/mol)
Mass of NaCl produced =0.552g
This study source was downloaded by 884789 from cliffsnotes.com on 04-04-2025 16:08:24 GMT -05:00
CHEM 120 - Week 3 -6.pdf
https://www.cliffsnotes.com//study-notes/24744256 CHEM 120 - Week 3 -6.pdf CHEM 120 - Week 3 -6.pdf
, CHEM 120 - Week 3 -6.pdf 8/20/2026 CHEM 120 - Week 3 -6.pdf
Part 2: Complete the Labster Lab: Solution Preparation: From salt to solution
Complete all activities and answer all questions within the lab and then complete the
questions below:
1. In this lab, you learned how to prepare solutions with a precise concentration.
Where in your nursing career might this skill be needed?
Preparing solutions with precise concentrations is a crucial skill in nursing for several
reasons:
● Medication Administration: Many medications are delivered in a concentrated
form and must be diluted before administration. The concentration must be
accurate to ensure the patient receives the correct dose.
● IV Fluids: Intravenous fluids often contain various solutes like electrolytes or
medications. Nurses must understand concentrations to prepare these fluids
correctly.
● Lab Work: Nurses may need to prepare solutions for certain lab tests. For
example, glucose tolerance tests require a precise concentration of glucose.
2. Which piece of glassware did you use to prepare your solution in this lab and
why?
In this lab a flask was used to prepared the solution and a beaker wasalso used. The
beaker was used to poor the solution and then transferred to the flask to avoid spelling.
The flask also had a long neck to avoid spilling and it is great to use for dilutions
3. Calculate how many grams of NaCl are required to make 100 mL of a 1 M NaCl
solution. Show your work in the space below.
Molar mass of NaCl is 58.44 g/mol
58.44 g of NaCl will be there in 1 M of 1 L NaCl solution.
100 mL 1 M NaCl solution.
(Mass = Molarity x molar mass x volume in liters)
Mass = (1mol/1L) x (58.44 g/mol) x (100L/1000) = 5.844 g
Reflection: Consider what you learned from these simulations. Reflect on three to four
key concepts that you learned in this lab exercise. How could the lessons learned in
this virtual lab relate to a real world situation in the community/world or your future
career as a nurse? Be specific in your answer (this should require 5-10 sentences).
This study source was downloaded by 884789 from cliffsnotes.com on 04-04-2025 16:08:24 GMT -05:00
CHEM 120 - Week 3 -6.pdf
https://www.cliffsnotes.com//study-notes/24744256 CHEM 120 - Week 3 -6.pdf CHEM 120 - Week 3 -6.pdf
