1 / 86

Chemical Quantities

Chemical Quantities. The Mole . But first…. CuCl 2 Na 3 PO 4 S 2 O 5 PbSO 4 ∙ 2H 2 O HNO 2 Silver acetate Gold (III) iodide Dinitrogen tetrabromide Cuprous nitrate tetrahydrate Hydrofluoric acid. Answers.

ernie
Download Presentation

Chemical Quantities

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chemical Quantities The Mole

  2. But first… • CuCl2 • Na3PO4 • S2O5 • PbSO4∙2H2O • HNO2 • Silver acetate • Gold (III) iodide • Dinitrogen tetrabromide • Cuprous nitrate tetrahydrate • Hydrofluoric acid

  3. Answers Pick out the mistake and write it down in your notes…do not say it out loud, or in a whisper, or in sign language, or in any way that would let someone else know the answer before they could figure it out on their own. • Copper (II) chloride or cupric chloride • Sodium phosphate • Dinitrogen pentoxide • Lead (II) sulfate dihydrate or plumbous sulfate dihydrate • Nitrous acid • Ag2C2H3O2 • AuI3 • N2Br4 • Cu(NO2)2 ∙ 4H2O • HF

  4. And second… The portfolio… Sections Notes—date each day, chronological order and not kept in a spiral notebook. HW—dated and put in chronological order Quests—see HW Tests—see HW General—everything that doesn’t have a home in the first set of sections goes here. Daily Journal…

  5. The Daily Journal • A statement of what was done that day. (We took notes over moles and Avogadro’s number). • ****A summary of your notes. Explain in detail in your own words what was covered in the notes for that day. Or explain what the purpose of the lab was, etc.**** • A couple statements about what you do not clearly understand or what you could not clearly describe in part #2 above. • What you are doing that night or what you have already done that night concerning this class.

  6. Ready?? Now we can begin with notes…

  7. Goals for Learning • To convert between moles and number of particles • To convert between mass and moles • To convert between moles and gas volume at STP • To use molarity in conversions involving solutions • To calculate the percent composition of a compound • To find an empirical formula from percent composition • To use an empirical formula to find a molecular formula

  8. Organization of Unit Volume of a solution Number of Moles Number of particles Mass Percent composition, empirical and molecular formulas Volume of a gas at STP

  9. Objectives • Explain what a mole is • Convert between moles and number of particles • Define molar mass • Find the molar mass of an element using the periodic table • Calculate the molar mass of a compound • Use molar mass to convert between mass and moles

  10. Key Terms • Mole (mol) • Avogadro’s number • Atomic mass • Molar mass

  11. Measuring Matter • All matter is made of different kinds of particles. • These particles can be molecules, atoms or ions. • Elements such as helium and iron exist as single atoms. • Other elements, like H, O and N are diatomic molecules. • Molecular compounds, like CO2 and water, also exist as molecules.

  12. Measuring Matter • Ionic compounds, like ammonium carbonate, consist of cations and anions in formula units. • Depending on the substance, different names for the particles are used. • In this unit, all atoms, molecules and formula units are referred to as particles.

  13. The Mole • The particles in matter are very, very small—too small to see, even with a microscope. • Counting the number of particles in a sample is not possible. • Instead of counting them, chemists measure the number of particles with a unit called the mole. • The abbreviation for mole is mol (I suppose there is a logical reason for this). • The mole is a unit for measuring the amount of substance.

  14. The Mole • The word mole means a number, similar to the word dozen. • 1 dozen eggs = 12 eggs • 1 mole eggs = 6.022 x 1023 eggs • One mole of any substance contains 6.022 x 1023 particles. • These particles can be atoms, molecules or formula units.

  15. The Mole • The number 6.022 x 1023 is called Avogadro’s number. • It is a very, very large number. • A mole of eggs is more eggs than have ever been eaten in the history of the world. • If you stacked a 6.022 x 1023 sheets of paper, the pile would reach to the sun and back more than a million times! • However a mole of molecules, atoms and formula units is not very big.

  16. Today… • Get ready for practice… • Notes to fill in the flow chart from Friday • Journals—in class—5 minutes before the bell—you must write the entire time…

  17. Time to Practice • NiCl2 • K3PO4 • S2Cl2 • H2CO3 • Cu(NO3)2 • Sodium hypochlorite • Silver bromide • Hydrochloric acid • Strontium permanganate • Sulfur trioxide

  18. Time to Practice • Nickel (II) chloride or nickelous chloride or #23 chloride • Potassium phosphate • Disulfur dichlorine • Hydrocarbonic acid • Copper (II) nitrate or Cupric nitrate • NaClO • AgBr • HCl • Sr(MnO4)2 • SO3

  19. Time to Recall • What is the date of Mole Day? • What time does it begin? End? • Write down the food you will be bringing in on Mole Day. • If you had a mole of bananas, how many bananas would you have? • What is this # called? (Name of dude?)

  20. Mole-Particle Conversions Volume of a solution Number of Moles Number of particles Mass Use Avogadro’s # of 1 mole = 6.022 X 1023 particles Percent composition, empirical and molecular formulas Volume of a gas at STP

  21. Mole-Particle Conversions • Chemists use Avogadro’s number to calculate the number of particles in a sample of matter. • Suppose you are told that balloon contains 2.00 mol of the gas argon–and nothing else. • You want to know how many particles are in the balloon. • You want to change the measurement units from moles to particles. • Moles Ar  particles Ar

  22. Mole-Particle Conversions • Your conversion factor is 1 mol Ar = 6.022 x 1023 particles Ar. • Write the given number and unit. Include the chemical symbol or formula of the substance. • Set up a factor label grid. • Use the conversion factor in the grid—making sure to align units so that they will cancel. • Give the answer with the correct unit and the correct number of significant digits.

  23. Mole-Particle Conversions • You try… • How many moles are in 4.35 x 1024 molecules of CO2? • How many formula units are in 3.15 mol of sodium oxide?

  24. Molar Mass • We know that 1 mole of a substance is a certain number of particles—regardless of what the particles are. • 1 mole of donuts is 6.022 x 1023 donuts • 1 mole of desks is 6.022 x 1023 desks • 1 mole of ¥ is 6.022 x 1023 ¥

  25. Molar Mass • 1 mole of a substance also has a certain mass—but it is different for every substance. • 1 mole of donuts does not have the same mass as 1 mole of desks, but they still contain the same number of each.

  26. Molar Mass • It is impossible to count the particles in a sample of matter but it is easy to find the sample’s mass. • If you know the mass of a substance, you can determine the number of moles in it. • To make a mass-to-mole conversion, you need to know about another piece of information from the periodic table. • Atomic number—number of protons and electrons in an atom • Atomic mass or molar mass is the mass of one atom of the substance or the mass of one mole of the substance.

  27. Molar Mass • If you want to know the atomic mass (mass of one atom) the number has units of amu (atomic mass units). • If you want to know the molar mass (mass of one mole of atoms) the number has units of g/mol (grams of substance per mole of substance).

  28. The Molar Mass of Elements • The molar mass of carbon is 12 g/mol. • The molar mass of oxygen is 16 g/mol. • This means that 6.022 x 1023 atoms of carbon (1 mol) has a mass of 12g. • This also means that 6.022 x 1023 atoms of oxygen (1 mol) has a mass of 16g.

  29. Review Mini • What is a dozen? • What is a mole? • How many atoms of H are in a dozen of H? • How many atoms of H are in a mole of H? • What is the mass of one H atom? • What is the mass of 1 mole of H atoms? • What is the mass of 1 O atom? • What is the mass of 1 mole of O atoms? • What is the mass of 1 mole of H2O?

  30. Today… • Short review time… • Get boards • Notes—molar mass, mass to mole conversions, gas volume to mole conversions, solution volume to mole conversions, percent composition and empirical formula concept… • HW—review 1 and 2 due tomorrow

  31. Review time… • CaI2 • NaNO3 • FeCl3 • SO2 • CoF2∙3H2O • Lithium nitride • Aluminum hydroxide • Carbon tetrabromide • Cupric nitrite • Magnesium acetate dihydrate

  32. Review time… • What number represents a mole? • How many moles of He is 6.35 x 1026 particles of He? • When you see that magnesium has a mass number of 24.31; what are the units we will be dealing with?

  33. Answers • Calcium iodide • Sodium nitrate • Iron (III) chloride or ferric chloride • Sulfur dioxide • Cobalt (II) fluoride trihydrate • Li3N • Al(OH)3 • CBr4 • Cu(NO2)2 • Mg(C2H3O2)2∙2H2O

  34. Answers • 6.022 x 1023 • 1050 moles • grams / mole

  35. The Molar Mass of Compounds • To find the molar mass of a compound of two or more elements, add the masses of 1 mol of each atom in the compound's formula or formula unit. • For example, to find the molar mass of CO2, count the number of C and O atoms in the formula.

  36. The Molar Mass of Compounds • Then locate the molar mass of carbon and oxygen on the periodic table. • Add the molar masses of each carbon an oxygen that make up the formula. • CO2 1 C and 2 O  C = 12.01g/mol, O = 16.0g/mol, O = 16.0g/mol = 44.01 g/mol • CO2  1C(12.01g/mol) + 2O(16.0g/mol) = 44.01 g/mol

  37. The Molar Mass of Compounds • You try… • Calculate the molar mass of the ionic compound, Ba(C2H3O2)2. • Calculate the molar mass of ammonium sulfate.

  38. Mole-Mass Conversions Volume of a solution Use molar mass in g/mol Number of Moles Number of particles Mass Percent composition, empirical and molecular formulas Volume of a gas at STP

  39. Mole-Mass Conversions • Molar mass can be used to convert between the mass of a sample and the number of moles in that sample. • If you know a sample’s mass, you can find the number of moles in the sample. • If you know how many moles are in a sample, you can find its mass. • Write the given number and unit as well as the formula for the substance.

  40. Mole-Mass Conversions • Set up a factor label grid. • Set up the conversion factor of grams per mole or moles per gram depending on your initial given information. • Use the atomic molar mass if converting atoms or use the molecular molar mass if converting compounds. • Write the answer with the correct units and the correct number of significant digits.

  41. Mole-Mass Conversions • Example: • What is the molar mass of carbon dioxide? • How many molecules are in 1 dozen carbon monoxide? • How many molecules are in 1 mole of carbon dioxide? • How many moles are in 26.52g of CO2? • What is the mass in grams of 3.25 mol of NaBr?

  42. Mini Quiz • How many grams are in 1.00 mole of calcium phosphate? • How many grams are in 3.20 moles of calcium phosphate? • How many molecules are in 4.12 moles of calcium phosphate? • How many molecules are in 298.58g of calcium phosphate? • How many grams in 3.24 x 1025 molecules of calcium phosphate? • What is the molarity of a solution that has 153.6g of Ca(NO3)2 in 1.2L of total solution? • How many liters does 402g of O2 gas take up at STP?

  43. Objectives • Define STP and standard molar volume • Convert between gas volume, moles, mass and number of particles • Calculate the molarity of a solution • Calculate the mass of solute • Calculate the volume of a solution

  44. Key Terms • Atmosphere • Standard temperature and pressure (STP) • Standard molar volume • Concentrated • Dilute • Concentration • Molarity

  45. Molar Volume Volume of a solution Number of Moles Number of particles Mass Percent composition, empirical and molecular formulas Use 1 mole of a gas at STP takes up 22.4L of space Volume of a gas at STP

  46. Molar Volume • Gases have a property that liquids and solids do not have. • Under certain conditions, 1 mol of any gas has a volume of 22.4L. • The two conditions that make this true are… • A temperature of 0ºC • A pressure of 1 atmosphere (atm)

  47. Molar Volume • Atmosphere (atm) is a unit for pressure. • The air pressure at sea level is a bout 1 atm. • The two conditions previously mentioned are standard temperature and pressure (STP). • For now it is important to know that 1 mol of any gas at STP has a volume of 22.4L. • This value is called standard molar volume.

  48. Molar Volume • For gases at STP, standard molar volume, 22.4L/mol, is used to convert between gas volume and moles. • This is a conversion factor that we can use in our factor label grid. • IMPORTANT: This conversion factor only works at STP!

  49. Molar Volume • Example: • What is the volume of 1.50 mol of CO2 @ STP? • You try… • How many moles are in 75.3L of O2 at STP?

  50. Molarity Conversions Volume of a solution Use molarity (M) in moles / L Number of Moles Number of particles Mass Percent composition, empirical and molecular formulas Volume of a gas at STP

More Related