Counting Atoms and Balancing Chemical Equations

  • Published on
    29-Jan-2016

  • View
    26

  • Download
    1

DESCRIPTION

Counting Atoms and Balancing Chemical Equations. Subscripts. C 12 H 22 O 11 There are 12 atoms of Carbon There are 22 atoms of Hydrogen There are 11 atoms of Oxygen If there is not a subscript listed, it is understood to be 1. NaCl There is one atom of Sodium There is one atom of Chlorine. - PowerPoint PPT Presentation

Transcript

<p>Counting Atoms and Balancing Chemical Equations</p> <p>Counting Atoms and Balancing Chemical Equations</p> <p>SubscriptsC12H22O11There are 12 atoms of CarbonThere are 22 atoms of HydrogenThere are 11 atoms of Oxygen</p> <p>If there is not a subscript listed, it is understood to be 1.NaClThere is one atom of SodiumThere is one atom of ChlorineLearning CheckNaHCO3Sodium 1Hydrogen 1Carbon 1Oxygen -3HClHydrogen 1Chlorine - 1There are times you will see a compound with parenthesis.Pb(NO3)2The 2 after the parenthesis indicates there are two sets of the parenthesis. Pb(NO3) (NO3)</p> <p>So, in counting the atoms, you would have the following:Lead 1 Oxygen 6 Nitrogen -2(NH4)3PO4</p> <p>Nitrogen 3Hydrogen 12Phosphorus 1Oxygen 4Mg(OH)2</p> <p>Magnesium 1Oxygen 2Hydrogen 2</p> <p>Learning Check2H2SO4This means there are 2 compounds of sulfuric acid. Think:H2SO4 + H2SO4</p> <p>Counting the atoms:Hydrogen 4 Sulfur 2Oxygen 8CoefficientCoefficient3H3PO4</p> <p>Hydrogen 9Phosphorus 3Oxygen - 122H2O</p> <p>Hydrogen 4Oxygen - 2Learning CheckReading Chemical EquationsThe mass of all the reactants (the substances going into a reaction) must equal the mass of the products (the substances produced by the reaction). </p> <p>CH4 + 2O2 CO2 + 2H2O</p> <p>ReactantsProductsLaw of Conservation of MassIn a chemical reaction, matter cannot be created or destroyed. It can only be changed.</p> <p>The reactants MUST contain the same elements and the same number of each element as the product. They CAN be in different compounds.Do the following equations follow the law of conservation of mass?H2 + O2 H2O Na + O2 Na2O Mg + 2HCl MgCl2 + H2 HgO Hg + O2N2 + 3H22NH32Na + 2H2O 2NaOH + H2Zn + 2HCl ZnCl2 + H2</p> <p>Learning CheckNO</p> <p>NO</p> <p>YES</p> <p>NO</p> <p>YES</p> <p>YES</p> <p>YES</p> <p>Na + O2 Na2O </p> <p>For this equation to be balanced, there must be equal amounts of Na in the reactants and products. </p> <p>You must add coefficients to balance this equation:2Na + O2 Na2O Balancing EquationsBalancing EquationsTwo waysM. I. N. O. H.orNumber charts</p> <p>Balancing EquationsM. I. N. O. H.</p> <p>Two waysAdd coefficients firstM - MetalsBalance metals such as Fe or Na first.Add coefficients firstM - MetalsBalance metals such as Fe or Na first.SecondI - IonsLooks for polyatomic ions (such as PO4-3 or SO4-2) that cross from reactant to product unchanged. Balance polyatomic ions as a group within its parentheses.Add coefficients firstM - MetalsBalance metals such as Fe or Na first.SecondI - IonsLooks for polyatomic ions (such as PO4-3 or SO4-2) that cross from reactant to product unchanged. Balance polyatomic ions as a group within its parentheses.ThirdN - Non-metalsChlorine (Cl) or Sulfur (S) are common non-metals to look for!Add coefficients firstM - MetalsBalance metals such as Fe or Na first.SecondI - IonsLooks for polyatomic ions (such as PO4-3 or SO4-2) that cross from reactant to product unchanged. Balance polyatomic ions as a group within its parentheses.ThirdN - Non-metalsChlorine (Cl) or Sulfur (S) are common non-metals to look for!FourthO - OxygenRemember, oxygen by itself is O2Add coefficients firstM - MetalsBalance metals such as Fe or Na first.SecondI - IonsLooks for polyatomic ions (such as PO4-3 or SO4-2) that cross from reactant to product unchanged. Balance polyatomic ions as a group within its parentheses.ThirdN - Non-metalsChlorine (Cl) or Sulfur (S) are common non-metals to look for!FourthO - OxygenRemember, oxygen by itself is O2Fifth (last)H - HydrogenRemember, hydrogen by itself is H2Balancing EquationsTwo waysNumber charts</p> <p>Balancing Equations __H2 + __O2 __H2OO -H -O -H -221222424 __H2SO4 + __NaOH __H2O +__Na2SO4Na -SO4 O H -Na -SO4 O H - 1113211222</p> <p>24224Balancing Equations __C3H8 + __O2 __CO2 +__H2OC -O H C -O H 3281323374108510Balancing Equations</p>

Recommended

View more >