160 likes | 361 Views
The activity series (P. 295). This lists elements according to their activity (their ability to react with other elements to form compounds) Elements at the top of the activity series are more active and can replace elements lower in the series in single or double replacement reactions
E N D
The activity series (P. 295) • This lists elements according to their activity (their ability to react with other elements to form compounds) • Elements at the top of the activity series are more active and can replace elements lower in the series in single or double replacement reactions • Li, K, Ba, Sr, Ca, Na, Mg, Al, Mn, Zn, Fe, Cd, Co, Ni, Sn, Pb, H, Cu, Ag, Hg, Au .
Activity Series (contd.) • For the following reactions, predict if they are possible and balance them….. • 1) Al+Fe(NO3)3 Fe+Al(NO3)3 • 2) Li+H2O LiOH+H2 • 3) FeSO4+ Cu CuSO4+ Fe • 4) Al2O3 + Fe Fe2O3 + Al
Chapter 10 – The Mole • An atom has a tiny mass (≈ 10-23 g ), we must therefore use an appropriately small unit…. The atomic mass unit or amu • Carbon -12 has a mass of exactly 12 amu • To find the formula mass of any molecule or unit of a compound, find the # of atoms of each element, multiply this # by atomic mass of the element and finally, add up all of the elements present.
Atomic mass and Formula Mass • Example: Find the formula mass of H2SO4. 2 X Hydrogen = 2 X1 = 2amu 1 X Sulfur = 1 X32 = 32amu 4 X Oxygen = 4 X 16 = 64amu Total Formula mass 98 amu
Find the formula mass each of the following substances….. • 1) Al+Fe(NO3)3 Fe+Al(NO3)3 • 2) Li+H2O LiOH+H2 • 3) FeSO4+ Cu CuSO4+ Fe • 4) Al2O3 + Fe Fe2O3 + Al
Moles • The number of atoms needed to make up an element’s atomic number in grams. • Example: 15.99g of Oxygen 63.55g of Copper 12.011g of Carbon 1.00g of Hydrogen All are composed of 6.02 X 1023 atoms The number is also known as Avogadro’s number
Moles and Molar Mass • For molecules (substances formed by atoms joined by covalent bonds) a mole of a compound is 6.02 X 1023 molecules of the compound. • Example: 1 mole of water has a mass of 2 X 1g = 2g + 1 X 16g = 16g 1mole of water = 18g and has 6.02 X 1023 molecules 18g/mol is known as the Molar Mass of a compound
How big is Avogadro’s number? • 6.02 X 1023 sheets of notebook paper stacked would go beyond our solar system. • 6.02 X 1023 footballs would form another planet bigger than the earth. • 6.02 X 1023 popcorn kernels would cover the land all over the USA 9 miles deep!
1 mole of pennies could be distributed to all the currently-living people of the world so that they could spend a million dollars per hour every hour (day and night) for the rest of their lives.
So far… • Formula Mass • Molar Mass • Did you notice that they are both numerically identical, different only in their units? • Now we will do some conversions….
Mole Mass & Mass Mole Conversions: • Remember conversion factors? • You multiply by a conversion factor that has the new units in the numerator and the old ones in the denominator…. • Depending on the direction we are going we will need the following conversion factors…… • grams/mol (molar mass!) or • mol/gram (get this by simply inverting grams/mol)
Mass MoleConversions: • Example: How many grams of NaCl is 2.5 moles of NaCl? • The Molar Mass of NaCl is 58.5 grams/mol • 2.5 mol NaCl X 58.5 g NaCl 1 mol NaCl = 146 g NaCl
Mass moles • Example: How many moles is 11.2 g of NaCl? • The Molar Mass of NaCl is 58.5 grams/mol 11.2 g NaCl X 1 mol NaCl = 0.191mol NaCl 58.5 g NaCl
moleparticle & particlemole conversions • You will use Avogadro’s # or it’s inverse • The two conversion factors are.. 6.02 X 1023 units 1 mol OR 1 mol 6.02 X 1023 units
Mole Particle Conversions: • Example: How many molecule units of water are there in 8.6 moles of water? • 8.6 mol X 6.02 X 1023 units 1 mol = 5.177 X 101 mol
Particle Mole Conversions: • Example: How many moles is 10.2 X1024 units of NaCl? • 10.2 X1024 units X 1 mol 6.02 X 1023 Units = 16.94 mol