The Mole Honors Chemistry Are these moles What

The Mole Honors Chemistry

Are these moles?

What is a mole? n A unit of measurement n Since the numbers in chemistry are so small, we use a “preferred unit of measurement” (mole) to represent the small number

What are the units of measurement? n n n "that equal number" of atoms arbitrarily chosen. the number of atoms in the atomic weight in g of any element. the number of atoms in 16 g of oxygen, in 4 grams of He, in 32 g of sulfur, etc. the number of molecules in the molecular weight, in grams, of any compound. the number of molecules in 18 g of water, in 40 g of lithium carbide. Much later, a mole, that equal number, was found to be 6. 022 x 1023(representative particles).

Examples n 1 mole (or abbr. mol) = 12. 011 g of Carbon n 1 mol of Carbon = 6. 02 x 1023 atoms of C n 1 mol of H 2 O = 6. 02 x 1023 molecules of water n 1 mol of Na. Cl = 6. 02 x 1023 units of Na. Cl

Moles in mass n 1 mole can equal the atomic weight of an element. q n 1 mol of C = 12. 011 g of C 1 mole can equal the atomic weight of a compound q 1 mol of CO = 12. 011 g of C + 15. 99 g of O = 28. 0 g of CO

Group Whiteboards n How many grams are in 1 mol of q q Nitrogen? Dinitrogen monoxide? **How many mols are in 100 g sample of N 2 O?

Warm Up #8 n n How many grams of Cu are in 1. 20 mol of Cu? How many moles are in 70 g of Cl?

Moles in compounds Let’s say you have water aka. H 2 O How many moles of Hydrogen atoms(ions) are in water? n Ask yourself how many individual atoms of Hydrogen do you see in water? n Did you say 2? ? ? n Is that your final answer? n You are correct! So how many mols of Oxygen atoms do you see?

Moles in an equation 2 H 2 + O 2 2 H 2 O How many moles of Hydrogen molecules are in the reactants? *Coefficients serve as the number of moles too! Therefore, there are 2 mols of Hydrogen gas

Molecules Atoms Units Mole Conversion Boomerang

Mole Conversions n Mass to mole or vice versa: q q How many moles are in 24 g of Carbon? Look at the boomerang: n n n Start with the given: 24 g (mass) of C What do you want in the end? Moles of C Use the conversion factor given: 1 mole Atomic mass 24 g of C x 1 mol of C = 2. 0 mol of Carbon 12. 011 g of C q

Brain Teaser n n Given 200 g of water, how many molecules of water do you have? How many liters of carbon dioxide are in 1. 5 x 10^33 molecules of carbon dioxide?

More conversion n Mole to particles or vice versa q q How many atoms are in 2. 00 mols of Carbon? Look at the boomerang: n n q Where do you begin? (the given: mols) What do you need in the end? (atoms: particles) What’s the conversion factor? n 6. 02 x 1023 Atoms of C 1 Mols of C 2. 00 mols of C x 6. 02 x 1023 atoms of C = 1. 20 x 1024 atoms C 1 mol of C

White boards How many molecules of oxygen gas are in 3. 0 mols of Oxygen gas? n How many mols of Oxygen gas are in 4. 67 x 1024 molecules of Oxygen gas? n

Final conversion!!! n n n Mole to moles of atoms or vice versa If you have 2. 00 mols of water, how many moles of hydrogen atoms are there? Look at the boomerang: q Mols mols of atoms(ions) CF: mols of H+ atoms mols of water 2. 00 mols of H 2 O x 2 mols of H+ atoms = 1 mol of H 2 O = 4. 00 mols of H+ atoms

Final conversion!!! n n n Mole to Volume (gas) or vice versa Any gas at STP (standard temperature and pressure) has a volume of 22. 4 L per mole Look at the cloud chart: q Mols volume of gas CF: Moles of gas 22. 4 L of gas Ex. How much volume of gas is in 5. 00 moles of H 2? 5. 00 moles H 2 x 22. 4 L of H 2 1 mole of H 2 = 122 L of H 2

Rally table n n Must show work (dimensional analysis) How many grams are in 1 mol of Mercury? Given a 1. 5 mols of carbon dioxide, how many molecules of carbon dioxide do you have? Given 3. 00 mols of carbon tetraflouride, how many mols of Flourine atoms are there in a compound?