1.1 What is Chemistry?

http://www.ck12.org Chapter 11. Chemical Reactions

Lesson Review Questions

1. Early Chinese alchemists discovered an early form of gunpowder. What was the composition of this sub-
   stance?


2. What later developments were made to the gunpowder recipe that improved its pyrotechnic properties?


3. Make an argument for why the burning of a candle is consistent with the law of conservation of matter/mass.


4. Think of an experiment that you could conduct to demonstrate that mass is conserved for a given chemical
   change.


5. Balance the following chemical equations:
   a. C+O 2 →CO
   b. CO+O 2 →CO 2
   c. H 2 +Br 2 →HBr
   d. K+H 2 O→KOH+H 2
   e. O 3 →O 2
   f. N 2 +H 2 →NH 3
   g. Zn+AgCl→ZnCl 2 +Ag
   h. Cl 2 +NaI→NaCl+I 2
   i. P 4 O 10 +H 2 O→H 3 PO 4
   j. Be 2 C+H 2 O→Be(OH) 2 +CH 4
   k. S+HNO 3 →H 2 SO 4 +NO 2 +H 2 O
   l. NH 3 +CuO→Cu+N 2 +H 2 O
   m. HCl+CaCO 3 →CaCl 2 +H 2 O+CO 2

Further Reading / Supplemental Links

• Youtube Video of Kaboom! The Sizzling Story of Explosions: http://www.youtube.com/watch?v=CShA5
  2EKY80


• Gunpowder in Ancient China: http://www.historyforkids.org/learn/war/gunpowder.htm


• Practice Balancing Chemical Equations:
  
  
  • http://education.jlab.org/elementbalancing/index.html
  
  
  • http://www.files.chem.vt.edu/RVGS/ACT/notes/scripts/bal_eq1.html
  
  
  • http://gregthatcher.org/Chemistry/BalanceEquation/S
  
  
  
  


• Chemical Equation Balances: http://www.personal.psu.edu/jzl157/balance.htm

Points to Consider

• What is the relationship between chemical equations and chemical reactions?


• In this chapter, an argument was made that the human fascination with fire and explosions ultimately con-
  tributed to our current understanding of chemical equations. Can you think of other aspects of nature for
  which further exploration has contributed to our current understanding of chemistry?