<p> Mole/mole problems</p><p>6.02 X 1023 objects is one mole. </p><p>The atomic mass of elements is the mass of one mole of that element, so </p><p>23 grams is the mass of one mole of Sodium and 35.4 grams is the mass of One mole of chlorine.</p><p>The formula weight (formula mass) of a compound is the mass of one mole of that compound. </p><p>H2SO4 H 2 X 1.0 = 2.0 S 1 X 32.0 = 32.0 O 4 x 16.0 = 64.0 98.0 FW or the (molar mass) of Hydrogen Sulfate.</p><p>Practice Problems </p><p>1. 40.0 grams of Sodium is how many moles of sodium?</p><p>40.0 g x 1 mole Na = ? Answer = 1.739 or 1.74 mole 23.0 g Na of Na</p><p>2. 200.0 g of Ba is how many moles ? </p><p>3. 175.0 g of Cu is how many moles? </p><p>4 Other way around , 4.5 moles of iron is how many grams? </p><p>4.5 moles Fe x 55.8 g Fe = 251.1 g Fe 1 mole </p><p>5 6.25 moles of Zn is how many grams?</p><p>6. 5.6 moles of CaCl2 is how many moles of CaCl2 Moving on to balanced equations </p><p>2H2 + O2 → 2H2O </p><p>This can be read as Two molecules of hydrogen plus one molecule of oxygen yields two Molecules of water. OR</p><p>Two moles of hydrogen plus one mole of oxygen yields two moles of water.</p><p>Remember a balanced equation is a recipe so if I started 10 moles of hydrogen instead of 2. I would need 5 moles of oxygen and would make 10 moles of water.( same ratio). </p><p>Let’s try another</p><p>2 KClO3 → 2 KCl + 3 O2 If we start with 9 moles of KClO3 instead of 2.</p><p>How many moles of oxygen would be formed? Using factor label we do the following.</p><p>9 moles KClO3 x 3 moles O2 = 13.5 moles O2 2 moles KCLO3</p><p>Notice the moles given ( KCLO3) cancels out leaving moles looking for.( oxygen).</p><p>So what are we doing? Take the moles given and mult by moles looking for over moles given in the equation. Which says for every 2 moles KCLO3 that decompose 3 moles of Oxygens are formed.</p><p>9 moles given x 3 moles looking for( from balance equation) = moles looking At start 2 Moles given ( from the balanced equation)</p><p>Practice </p><p>1. Zn + 2 HCl → ZnCl2 + H2</p><p>If 8 moles of HCl react how many moles of hydrogen will be formed? I know it’s easy, but set it up as a factor label problem so you learn how! It won’t be easy later.</p><p>+2 2. 3 Cu + 2 Bi(NO3)3 → 3 Cu(NO3 )2 + 2Bi </p><p>If 15 Moles of copper react in the above equation, how many moles of bismuth Will be formed? 4. If 25.0 moles of aluminum dust is added to a solution of silver nitrate, how moles of silver could be recovered? Hint you have to write the balanced equation first.</p><p>5. C2H5OH + 3 O2 → 2 CO2 + 3 H2O </p><p>If 7.5 moles of alcohol is burned how many moles of water will be formed? Show factor label? Part 2 how many grams of water is this?</p><p>6. When 35 moles of Al2(CO3)3 decomposes, how many moles of carbon dioxide will be released? </p>