1. Why do chemical reactions work so perfectly?

2. Pick your best answer in your pairs
on a whiteboard, face down and secure.

3. Which one below is a REAL chemical reaction?
NaOH + H2O2  NaCl + H2O
NaCl + H2O  H2O + NaCl
NaOH + HCl  NaCl + H2O
NaCl + HCl  HCl + H2O

4. Write down your answer and place it face down on your desk.

5. This one doesn’t do anything.
NaOH + H2O2  NaCl + H2O
NaCl + H2O  H2O + NaCl
NaOH + HCl  NaCl + H2O
NaCl + HCl  HCl + H2O

6. This one is just a mixture.
NaOH + H2O2  NaCl + H2O
NaCl + H2O  H2O + NaCl
NaOH + HCl  NaCl + H2O
NaCl + HCl  HCl + H2O

7. gotta love salt water!

8. Why doesn’t this one make sense?
NaOH + H2O2  NaCl + H2O
NaCl + H2O  H2O + NaCl
NaOH + HCl  NaCl + H2O
NaCl + HCl  HCl + H2O

9. Why doesn’t this one make sense?
NaOH + H2O2  NaCl + H2O
NaCl + H2O  H2O + NaCl
NaOH + HCl  NaCl + H2O
NaCl + HCl  HCl + H2O

10. Where did this oxygen atom come from?
NaOH + H2O2  NaCl + H2O
NaCl + H2O  H2O + NaCl
NaOH + HCl  NaCl + H2O
NaCl + HCl  HCl + H2O
?????

11. We can’t have 2 chlorines in the reactants and only 1 in the products!
NaOH + H2O2  NaCl + H2O
NaCl + H2O  H2O + NaCl
NaOH + HCl  NaCl + H2O
NaCl + HCl  HCl + H2O
?????

12. Are the NUMBERS right in A?
NaOH + H2O2  NaCl + H2O
NaCl + H2O  H2O + NaCl
NaOH + HCl  NaCl + H2O
NaCl + HCl  HCl + H2O

13. What happened to the 3 reacting oxygen atoms in the beginning
What happened to the 3 reacting oxygen atoms in the beginning? Now there’s only 1 in the product?
NaOH + H2O2  NaCl + H2O
NaCl + H2O  H2O + NaCl
NaOH + HCl  NaCl + H2O
NaCl + HCl  HCl + H2O

14. And where did this chlorine come from????
NaOH + H2O2  NaCl + H2O
NaCl + H2O  H2O + NaCl
NaOH + HCl  NaCl + H2O
NaCl + HCl  HCl + H2O

15. That leaves us with only one!
NaOH + H2O2  NaCl + H2O
NaCl + H2O  H2O + NaCl
NaOH + HCl  NaCl + H2O
NaCl + HCl  HCl + H2O

16. Why is “C” the legit reaction?
NaOH + H2O2  NaCl + H2O
NaCl + H2O  H2O + NaCl
NaOH + HCl  NaCl + H2O
NaCl + HCl  HCl + H2O

17. Why is “C” the legit reaction?
NaOH + H2O2  NaCl + H2O
NaCl + H2O  H2O + NaCl
NaOH + HCl  NaCl + H2O
NaCl + HCl  HCl + H2O
Reactants have the same atoms,
but just are re-made into different
molecular products.

18. CHEMICAL REACTIONS DON’T make matter out of thin air!
impossible
NaOH + H2O2  NaCl + H2O
NaCl + H2O  H2O + NaCl
NaOH + HCl  NaCl + H2O
NaCl + HCl  HCl + H2O
impossible

19. How many had that right?
LET’S TRY A COUPLE MORE…

20. Which is a REAL CHEMICAL REACTION?
ZnSO4 + Cu  CuSO4
2 Fe + 6 HCl  2 FeCl3 + 3 H2
Cl2 + 2 K(OH)  H2 + 2 KCl
CaBr2 + AgO3  AgBr + 2 CaNO3

21. BOARDS FACE DOWN!

22. Why is A not a real reaction?
What element are we missing in the product?
ZnSO4 + Cu  CuSO4
2 Fe + 6 HCl  2 FeCl3 + 3 H2
Cl2 + 2 K(OH)  H2 + 2 KCl
CaBr2 + AgO3  AgBr + 2 CaNO3

23. What happened to the zinc in the product?
ZINC didn’t just disappear from this reaction!
ZnSO4 + Cu  CuSO4
2 Fe + 6 HCl  2 FeCl3 + 3 H2
Cl2 + 2 K(OH)  H2 + 2 KCl
CaBr2 + AgO3  AgBr + 2 CaNO3

24. In CHEMICAL REACTIONS, matter does NOT just DISAPPEAR!
And wasn’t there an oxygen atom in the reactants here? Where did it go?
ZnSO4 + Cu  CuSO4
2 Fe + 6 HCl  2 FeCl3 + 3 H2
Cl2 + 2 K(OH)  H2 + 2 KCl
CaBr2 + AgO3  AgBr + 2 CaNO3
No O!!!
In CHEMICAL REACTIONS, matter does NOT just DISAPPEAR!

25. Where did the nitrogen atom come from??
ZnSO4 + Cu  CuSO4
2 Fe + 6 HCl  2 FeCl3 + 3 H2
Cl2 + 2 K(OH)  H2 + 2 KCl
CaBr2 + AgO3  AgBr + 2 CaNO3

26. The correct chemical reaction formula is B!
ZnSO4 + Cu  CuSO4
2 Fe + 6 HCl  2 FeCl3 + 3 H2
Cl2 + 2 K(OH)  H2 + 2 KCl
CaBr2 + AgO3  AgBr + 2 CaNO3

27. CHEMICAL REACTIONS DON’T MAKE MATTER OUT OF THIN AIR!
Reactants have the same atoms,
but just are re-made into different
molecular products.
CHEMICAL REACTIONS DON’T MAKE MATTER OUT OF THIN AIR!
In CHEMICAL REACTIONS, matter does NOT just DISAPPEAR!

28. How many had that right?
LET’S TRY ONE MORE…

29. Which ONE is a REAL chemical reaction?
2 C8H O2  18 H2O + 16 CO2
6 CO H2S  C6H12O H2O S
C3N6H6O6 + O2  3 CO2 + 2 H2O + 2 N2 + H2
Ba(OH)2 + 6 H2O + 2 NH4Cl  2NH3 + 10H2O + BaCl2
When you are done, put your boards face down.

30. C isn’t right…There are 6 nitrogen atoms in the reactants, but only 4 in the products!
2 C8H O2  18 H2O + 16 CO2
6 CO H2S  C6H12O H2O S
C3N6H6O6 + O2  3 CO2 + 2 H2O + 2 N2 + H2
Ba(OH)2 + 6 H2O + 2 NH4Cl  2NH3 + 10H2O + BaCl2

31. What’s wrong with B? 2 C8H18 + 25 O2  18 H2O + 16 CO2
6 CO H2S  C6H12O H2O S
C3N6H6O6 + O2  3 CO2 + 2 H2O + 2 N2 + H2
Ba(OH)2 + 6 H2O + 2 NH4Cl  2NH3 + 10H2O + BaCl2

32. Count up your sulfurs on both sides of the reaction…
2 C8H O2  18 H2O + 16 CO2
6 CO H2S  C6H12O H2O S
C3N6H6O6 + O2  3 CO2 + 2 H2O + 2 N2 + H2
Ba(OH)2 + 6 H2O + 2 NH4Cl  2NH3 + 10H2O + BaCl2

33. 6 S on the reactants, 12 S on the products.
2 C8H O2  18 H2O + 16 CO2
6 CO H2S  C6H12O H2O S
C3N6H6O6 + O2  3 CO2 + 2 H2O + 2 N2 + H2
Ba(OH)2 + 6 H2O + 2 NH4Cl  2NH3 + 10H2O + BaCl2

34. CHEMICAL REACTIONS DON’T make matter out of thin air!
Reactants have the same atoms,
but just are re-made into different
molecular products.
CHEMICAL REACTIONS DON’T make matter out of thin air!
In CHEMICAL REACTIONS, matter does NOT just DISAPPEAR!

35. Did you notice anything off about D?
2 C8H O2  18 H2O + 16 CO2
6 CO H2S  C6H12O H2O S
C3N6H6O6 + O2  3 CO2 + 2 H2O + 2 N2 + H2
Ba(OH)2 + 6 H2O + 2 NH4Cl  2NH3 + 10H2O + BaCl2

36. We have only 22 hydrogens & 8 oxygens in the reactants, but 26 H & 10 O after.
2 C8H O2  18 H2O + 16 CO2
6 CO H2S  C6H12O H2O S
C3N6H6O6 + O2  3 CO2 + 2 H2O + 2 N2 + H2
Ba(OH)2 + 6 H2O + 2 NH4Cl  2NH3 + 10H2O + BaCl2

37. The CORRECT chemical reaction is A.
2 C8H O2  18 H2O + 16 CO2
6 CO H2S  C6H12O H2O S
C3N6H6O6 + O2  3 CO2 + 2 H2O + 2 N2 + H2
Ba(OH)2 + 6 H2O + 2 NH4Cl  2NH3 + 10H2O + BaCl2
WHO PICKED A?

38. Now they are ALL real. 2 C8H18 + 25 O2  18 H2O + 16 CO2
6 CO H2S  C6H12O H2O S
C3N6H6O6 + O2  3 CO2 + 2 H2O + 3 N2 + H2
Ba(OH)2 + 8 H2O + 2 NH4Cl  2NH3 + 10H2O + BaCl2

39. COLLECT BOARDS AND MARKERS.

40. In chemical reactions, matter DOES NOT magically appear nor DISAPPEAR.

41. Remember our chemical reaction to rip apart the water molecule?

42. 2 H2O  2 H2 + O2

43. Were we able to see the two gases coming apart from 2 water molecules?
OXYGEN GAS (O2) like to react with other atoms!
HYDROGEN GAS (H2) is MUCH MORE EXPLOSIVE gas!
to form rust/corrosion
to keep fires burning
can explode on its own!

44. NEW SUBSTANCES are REFORMED from the SAME OLD ATOMS!
2 H2O  2 H2 + O2

45. NEW SUBSTANCES are REFORMED from the SAME OLD ATOMS!
2 H2O  2 H2 + O2
the LAW of
CONSERVATION
of MATTER (mass)

46. In CHEMICAL REACTION, MATTER is NOT CREATED, it is NOT DESTROYED.
2 H2O  2 H2 + O2 2 CH2 + 3 O2  2 CO2 + 2 H2O 6 CO2 + 6 H2O  C6H12O6 + 6 O2

47. In chemical reactions, MATTER is NOT CREATED, NOT DESTROYED.
2 H2O  2 H2 + O2 2 CH2 + 3 O2  2 CO2 + 2 H2O 6 CO2 + 6 H2O  C6H12O6 + 6 O2
The same atoms are just REARRANGED
into NEW MOLECULES.

48. In chemical reactions, MATTER is NOT CREATED, NOT DESTROYED.
the LAW of
CONSERVATION
of MATTER (mass)
2 H2O  2 H2 + O2 2 CH2 + 3 O2  2 CO2 + 2 H2O 6 CO2 + 6 H2O  C6H12O6 + 6 O2
The same atoms are just REARRANGED
into NEW MOLECULES.

49. conservation of matter AND MASS