University:
San Jose State University
Course:
CHEM 10 | Chemical Calculations and Concepts
Academic year:

2022
Views:

68

Pages:

3
Author:

RonoEnduh6sl

PAL— More Mol Calculations Part I: Chemical Formulae as Conversion Factors By this point you should be comfortable converting grams ßà molesßà number of atoms or molecules for any element or compound. Next we will add chemical formulae as conversion factors to our toolbox. For example, if we wanted to convert between moles of NH3 and moles of H atoms, we see that every 1mole of NH3 has 3 moles of H atoms, which leads to the conversion factor. 3 mol H atoms 1 mol NH3 or 1 mol NH3 3 mol H atoms 1. The following question refers to copper (II) sulfate. Show all your work with correct units and report your answer with correct signiﬁcant ﬁgures and units. a. What is the formula for copper (II) sulfate?___________________ b. Write a conversion factor that relates the moles of oxygen atoms to the moles of copper (II) sulfate. c. Using the conversion factor from question 1b, determine how many moles of O atoms are present in 15.8 moles of copper (II) sulfate. d. Using the conversion factor from question 1b, determine how many moles of copper (II) sulfate you must have if you have a sample of a sample of copper (II) sulfate containing 2.50 moles of O atoms. 1 We can expand upon the ﬂowchart used on the previous worksheet to now go between diRerent molecules or elements in a chemical reaction. The conversion factor in the below chart is seen as the “ratio from chemical formula.” This allows us to determine the relative quantity of one element or compound, X, to another, Y. Use the ﬂowchart to answer question 2. 2. Potassium permanganate is commonly used to treat a variety of skin conditions. How many iodine atoms are there in 2.8 grams of potassium permanganate? When using the above ﬂowchart, replace X with potassium permanganate, and Y with Mn. a. What is the formula for potassium permanganate?______________ b. Write a conversion factor that relates the moles of Mn atoms to the moles of potassium permanganate. c. Using the ﬂowchart as a guide, write out your plan for determining the number of Mn atoms in 2.8 grams of potassium permanganate. Be sure to write all the units in your ﬂowchart. Units are more important than ever now that we are dealing with multiple atoms and molecules. 2 d. Finally, use the plan you just created in 2c to calculate how man y Mn atoms are in 2.8 grams of potassium permanganate. Show all your work, including ALL units, for this calculation. Report your answer with the correct number of signiﬁcant ﬁgures. 3. Now, let’s use the ﬂowchart as a guide for an entire chemical reaction. We will use this ﬂowchart to determine how much silver sulfate can be made from 5.3 grams of lithium sulfate. a. Balance the following reaction: _____ LiSO4 (aq) + _____ AgClO3 (aq) à _____ Ag2SO4 (s) + _____ LiClO3 (aq) b. Use your balanced chemical equation from above, determine the mole to mole ratio of lithium sulfate to silver sulfate. c. Use the mole to mole ratio from 3b to determine how many grams of silver sulfate can be made from 5.3 grams of lithium sulfate. 3