Presentation Transcript

1. Balancing Equations Yes We can!!! Can We Do It?

2. + O O  H H H H O H2 + O2 H2O Make your molecules with marshmallows and toothpicks. Now take an inventory: H ___ O ___ 2 H ___ O ___ 2 2 1 Balanced? Nope, now what?

3. O O H H H H O +  • The molecules themselves cannot be changed but there must be the same number of each type of atom on each side of the yields sign in order to be balanced. • When adding a coefficient to the equation, it will multiply the number of each type of atom in that formula.

4. O O H H H H O +  O H H H2 + O2 H2O 2 Now we have: H ___ O ___ 2 H ___ O ___ 4 Still not balanced! 2 2

5. O O +  H H H H O O H H H H 2 H2 + O2 H2O 2 Now we have: H ___ O ___ 4 H ___ O ___ 4 TaDa!! 2 2

6. Cl Cl Cl + Na  + Mg Mg Na Na + MgCl2 NaCl + Mg Na ___ Mg ___ Cl ___ 1 Na ___ Mg ___ Cl ___ 1 1 1 2 1 Not balanced

7. Cl Cl Cl Cl Na Mg Mg Na Na 2 Na + MgCl2 NaCl + Mg + +  With 2 Cl’s on the reactant side, we want to make 2 Cl’s on the products side… Na ___ Mg ___ Cl ___ 1 Na ___ Mg ___ Cl ___ 2 Not balanced yet… Now we have: 1 1 2 2

8. Cl Cl Cl Cl Na Na Mg Mg Na Na 2 Na + MgCl2 2 NaCl + Mg + +  Now we need to even up our sodiums (Na’s) Na ___ Mg ___ Cl ___ 2 Na ___ Mg ___ Cl ___ 2 Take inventory: Yippee!! 1 1 2 2

9. O O O  H H H C O H C H O H CH4 + O2 CO2 + H2O C ___ H ___ O ___ C ___ H ___ O ___ 1 1 Not balanced 4 2 2 3

10. O H H H H H C O O H C H O H CH4 + O2 CO2 + H2O 2 O  O C ___ H ___ O ___ 1 C ___ H ___ O ___ 1 4 Nope, not yet… 4 2 4

11. O H H H H H C O O H C H O O O H CH4 + O2 CO2 + H2O 2 2 O  O C ___ H ___ O ___ 1 C ___ H ___ O ___ 1 4 4 WooHoo!! 4 4

12. Now let’s try some without the marshmallows….. Al2O3 + H2 H2O + Al 3 3 2 Don’t forget to box off your formulas so you don’t mess with them! Inventory: Wedidit!! Al ___ O ___ H ___ 2 Al ___ O ___ H ___ 1 2 3 1 3 6 2 6 2

13. Fe + O2 Fe2O3 4 3 2 I think we’ve got it!! 1 4 Fe ___ O ___ Fe ___ O ___ 4 2 6 3 6 This one’s tricky—start with oxygen and use the lowest common denominator.

14. The End!