Stoichiometry: Molar Conversions

What is the Mole? A counting number (like a dozen) Avogadro’s number 1 mole = 6.02  1023 items

How Much is a Mole? 1 mole of hockey pucks would equal the mass of the moon! 1 mole of basketballs would fill a bag the size of the earth!

Molar Mass: the mass of 1 mole of a substance (element or compound) 11 Na 22.989707 Atomic mass tells the: atomic mass units per atom (amu) grams per mole (g/mol) Round to 2 decimal places

There are 12 particles in the nucleus of a Carbon atom There are 12 particles in the nucleus of a Carbon atom. The mass of 1 atom of Carbon = 12 amu The mass of 602,200,000,000,000,000,000,000 atoms of Carbon = 12 grams

Molar Mass of Atoms 6.94 g/mol 26.98 g/mol 132.91 g/mol Lithium Aluminum Cesium 6.94 g/mol 26.98 g/mol 132.91 g/mol

Molar Mass of Compounds H2O 2(1.01) + 16.00 = 18.02 g/mol NaCl 22.99 + 35.45 = 58.44 g/mol

Molar Mass Examples NaHCO3 22.99 + 1.01 + 12.01 + 3(16.00) = 84.01 g/mol C12H22O11 12(12.01) + 22(1.01) + 11(16.00) = 342.34 g/mol

Molar Conversions molar mass 6.02  1023 (g/mol) (particles/mol) MOLES IN GRAMS MOLES NUMBER OF PARTICLES (g/mol) (particles/mol)

When to Use Molar Mass (from chart): When converting the same substance from g  mol mol g REMEMBER: Mass Number= number grams in 1 mole of the substance Can use mol/g or g/mol

How many moles of carbon are in 26 g of carbon? Practice Problem #1 How many moles of carbon are in 26 g of carbon? 26 g C 1 mol C 12.01 g C = 2.2 mol C

How many grams of carbon are in 5moles of carbon? Practice Problem #2 How many grams of carbon are in 5moles of carbon? 5 mol C 12.01 g C 1mol C = 60g C

How many moles of CO2 are in 26 g of CO2? Practice Problem #3 How many moles of CO2 are in 26 g of CO2? 26 g CO2 1 mol CO2 44.01 g CO2 =.59 mol CO2

How many grams of CO2 are in 3 mol of CO2? Practice Problem #4 How many grams of CO2 are in 3 mol of CO2? 3 mol CO2 44 g CO2 1 mol CO2 =132 g CO2

Molar Conversions molar mass 6.02  1023 (g/mol) (particles/mol) MOLES IN GRAMS MOLES NUMBER OF PARTICLES (g/mol) (particles/mol)

When to Use Avogadro's Number: When converting the same substance from g  number of particles number of particles  g mol number of particles Number of particles  mol REMEMBER: Avogadro's Number = 6.022 x 1023 Can use mol/particles or particles/mol

How many molecules are in 2.50 moles of C12H22O11? Practice Problem #1 How many molecules are in 2.50 moles of C12H22O11? 6.02  1023 molecules 1 mol 2.50 mol = 1.51  1024 molecules C12H22O11

Find the mass of 2.1  1024 molecules of NaHCO3. Practice Problem #2 Find the mass of 2.1  1024 molecules of NaHCO3. 2.1  1024 molecules 1 mol 6.02  1023 molecules 84.01 g 1 mol = 290 g NaHCO3

When to Use Mole Ratio (from equation): When converting from one substance to another REMEMBER: Coefficient tells you the number of moles of each sustance

How many moles of O2 can be produced from 12.00 moles of NaClO3? Practice Problem #1 2NaClO3  2NaCl + 3O2 How many moles of O2 can be produced from 12.00 moles of NaClO3? 12 mol NaClO3 3 mol O2 2 mol NaClO3 = 18 mol O2

How many moles of NaCl can be produced from 10.00 moles of NaClO3? Practice Problem #2 2NaClO3  2NaCl + 3O2 How many moles of NaCl can be produced from 10.00 moles of NaClO3? 10 mol NaClO3 2 mol NaCl 2 mol NaClO3 = 10 mol NaCl

Practice Problem #3 KOH + HCl KBr + H2O = 21.21 g KBr 10 g KOH If you start with 10 grams of potassium hydroxide, how many grams of potassium bromide can be made? Molar Mass Mole Ratio Molar Mass 10 g KOH 1 mol KOH 56.11 g KOH 1 mol KBr 1 mol KOH 119 g KBr 1 mol KBr = 21.21 g KBr

Practice Problem #4 Si2H4 + 3O2 2SiO2+ 2H2O = 89.81g SiO2 45 g Si2H4 If you start with 45 grams of Si2H4, how many grams of SiO2 can be made? 45 g Si2H4 1 mol Si2H4 60.22 g Si2H4 2 mol SiO2 1 mol Si2H4 60.09g SiO2 1 mol SiO2 = 89.81g SiO2