Round all masses to the 10ths place

 Step One: two atoms of iron and three of oxygen  Step Two: Fe = 55.8 amu and O = 16.0 amu  Step Three: (2 x 55.8) + (3 x 16.0)  Step Four: = amu (grams) for one mole

 Step One: one atom of potassium, one of chlorine, and four of oxygen.  Step Two: K = 39.1 amu, Cl = 35.5 amu, O = 16.0 amu  Step Three: (1 x 39.1) + (1 x 35.5) + (4 x 16.0)  Step Four: = amu (grams) for one mole

 Step One: two atoms of nitrogen, eight of hydrogen and one of sulfur  Step Two: N = 14.0 amu, H = 1.0 amu, S = 32.1 amu  Step Three: (2 x 14.0) + (8 x 1.0) + (1 x 32.1)  Step Four: = 68.1 amu (grams) for one mole

 Calculate the molar mass of Al(NO 3 ) 3  Al(1 x 27.0) + N(3 x 14.0) + O(9 x 16.0) =  amu (grams) is the mass of one mole of aluminum nitrate.

 1. AlCl 3  2. Ba(SCN) 2  3. LiH  4. Ba(BrO 3 ) 2  5. AlBr 3  6. HCl

 g/mol  g/mol  g/mol  g/mol  g/mol  g/mol

Round all final answers to 3 sig figs

 KMnO 4 = g / mole of KMnO 4  Now let’s solve it  25.0 g x 1 mole = moles g  moles

 H 2 O 2 = 34.0 g / mole  Now, let’s solve it  17.0 g x 1 mol H 2 O 2 = 0.5 moles 34.0 g  moles

 Calculate the moles present in:  1) 2.00 grams of H 2 O  2) grams of KBr  3) 100. grams of KClO 4  4) 8.76 grams of NaOH  5) grams of Na 2 CO 3  Remember to round answers to 3 sig figs

 1)0.111 moles  2)0.635 moles  3) moles  4)0.219 moles  5) moles

Round all answers to 3 sig figs

 H 2 O 2 molar mass = 34.0 grams/mole  moles x 34.0 grams = 23.8 g 1 mole  23.8 grams

 KClO 3 molecular mass = g/mole  2.50 moles x g = grams 1 mole  307 grams

 Calculate the grams present in:  1) moles of H 2 S  2) moles of KI  3) moles of KClO  4) moles of NaOH  5) 3.40 x moles of Na 2 CO 3  Remember to round answer to 3 sig figs

 1)6.82 grams  2)16.6 grams  3)136 grams  4)30.0 grams  5) grams

6.02 x particles = 1 mole Particles can mean atoms or molecules

 One mole of donuts contains 6.02 x donuts  One mole of H 2 O contains 6.02 x molecules  One mole of nails contains 6.02 x nails  One mole of Fe contains 6.02 x atoms

 One mole of dogs contains 6.02 x dogs  One mole of electrons contains 6.02 x electrons  One mole of Chemistry students contains 6.02 x poor, suffering (I mean happy, joyful) high school students

 mole Fe x 6.02 x atoms 1 mole  = 2.709x10 23 atoms  Final, rounded answer: 2.71x10 23 atoms

 mole x 6.02 x atoms 1 mole  = 1.204x10 23 atoms  Final, rounded answer: 1.20x10 23 atoms

 1) Calculate the number of molecules in mole of H 2 O  2) Calculate the number of atoms in mole of Fe  Remember to round to 3 sig figs

 1)6.37x10 23 molecules  2)4.52x10 23 atoms

Grams to particles OR particles to grams Grams to atoms OR atoms to grams If MOLE is not stated, it’s a two step problem ROUND ALL ANSWERS TO 3 SIG FIGS

 g x 1 mole Fe x 6.02x10 23 atoms = 55.8 g 1 mole  x10 21 atoms  Final answer = 4.85x10 21 atoms

 H 2 O molecular mass = 18.0 g  g x 1 mole H 2 O x 6.02x10 23 molecules 18.0 g 1 mole  x10 21 molecules  Final answer = 6.69x10 21 molecules

 1) Calculate the number of molecules in gram of H 2 O  2) Calculate the number of atoms in gram of Fe  Remember to round answer to 3 sig figs

 1)3.54x10 22 molecules  2)8.10x10 21 atoms