1. Chemical Reactions & Review Problems

2. 2KClO 3 2KCl + 3O 2 Element Symbol Element NameElement Subscript Times X Coefficient Number Total # of atoms K potassium 1X22 Cl Chlorine 1X22 O oxygen 3X26 Answer is based on the using the elements on the REACTANT side of chemical reaction.

3. HCl + NaOH NaCl + H 2 O Element Symbol Element NameElement Subscript Times X Coefficient Number Total # of atoms Na sodium 1X11 Cl Chlorine 1X11 O oxygen 1X11 H hydrogen 2X12 Answer is based on the using the elements on the PRODUCT side of chemical reaction.

4. Mg+ 2HCl MgCl 2 + H 2 Element Symbol Element NameElement Subscript Times X Coefficient Number Total # of atoms Mg magnesium 1X11 Cl chlorine 2X12 H hydrogen 2X12 Answer is based on the using the elements on the PRODUCT side of chemical reaction.

5. 2H 2 + O 2 2H 2 O Element Symbol Element NameElement Subscript Times X Coefficient Number Total # of atoms H hydrogen 2X24 O oxygen 2X12 Answer is based on the using the elements on the REACTANT side of chemical reaction.

6. 2Al + 3NiBr 2 2AlBr 3 + 3Ni Element Symbol Element NameElement Subscript Times X Coefficient Number Total # of atoms Al Aluminum 1X22 Br Bromine 3X26 Ni nickel 1X33 Answer is based on the using the elements on the PRODUCT side of chemical reaction.

7. 4Al + 3O 2 2Al 2 O 3 Element Symbol Element NameElement Subscript Times X Coefficient Number Total # of atoms Al Aluminum 2X24 O oxygen 3X26 Answer is based on the using the elements on the PRODUCT side of chemical reaction.

8. 2NaCl 2Na + Cl 2 Element Symbol Element NameElement Subscript Times X Coefficient Number Total # of atoms Na Sodium 1X22 Cl chlorine 1X22 Answer is based on the using the elements on the REACTANT side of chemical reaction.

9. CaCl 2 + F 2 CaF 2 + Cl 2 Element Symbol Element NameElement Subscript Times X Coefficient Number Total # of atoms Ca calcium 1X11 Cl chlorine 1X22 F fluorine 2X12 Answer is based on the using the elements on the REACTANT side of chemical reaction.

10. AgNO 3 + KCl AgCl + KNO 3 Element Symbol Element NameElement Subscript Times X Coefficient Number Total # of atoms Ag silver 1X11 Cl chlorine 1X11 K potassium 1X11 N Nitrogen 1X11 O Oxygen 3X13 Answer is based on the using the elements on the PRODUCT side of chemical reaction.

11. N 2 + 3H 2 2NH 3 Element Symbol Element NameElement Subscript Times X Coefficient Number Total # of atoms N Nitrogen 2X12 H Hydrogen 2X36 Answer is based on the using the elements on the REACTANT side of chemical reaction.

12. 2H 2 O 2 2H 2 O + O 2 Element Symbol Element NameElement Subscript Times X Coefficient Number Total # of atoms O Oxygen 2X24 H Hydrogen 2X24 Answer is based on the using the elements on the REACTANT side of chemical reaction.

13. MgI 2 + Br 2 MgBr 2 + I 2 Element Symbol Element NameElement Subscript Times X Coefficient Number Total # of atoms Mg magnesium 1X11 I Iodine 2X12 Br Bromine 2X12 Answer is based on the using the elements on the PRODUCT side of chemical reaction.

14. SO 3 + H 2 O H 2 SO 4 Element Symbol Element NameElement Subscript Times X Coefficient Number Total # of atoms H Hydrogen 2X12 S sulfur 1X11 O oxygen 4X14 Answer is based on the using the elements on the PRODUCT side of chemical reaction.

15. 2KClO 3 2KCl + 3O 2 What type of reaction is the above reaction? The REACTANTS are breaking down into smaller molecules. Therefore a DECOMPOSITION reaction is the result.

16. HCl + NaOH NaCl + H 2 O What type of reaction is the above reaction? The elements in the REACTANTS are switching with each other to become new molecules. Therefore a DOUBLE REPLACEMENT reaction is the result.

17. Mg+ 2HCl MgCl 2 + H 2 What type of reaction is the above reaction?. The elements in the REACTANTS are switching with each other to become new molecules. Therefore a SINGLE REPLACEMENT reaction is the result.

18. 2H 2 + O 2 2H 2 O What type of reaction is the above reaction? The elements in the REACTANTS are COMBINING with each other to become new molecules. Therefore a SYNTHESIS or ADDITION or BIOSYNTHESIS reaction is the result.

19. 2Al + 3NiBr 2AlBr 3 + 3Ni What type of reaction is the above reaction? The elements in the REACTANTS are switching with each other to become new molecules. Therefore a SINGLE REPLACEMENT reaction is the result.

20. 4Al + 3O 2 2Al 2 O 3 What type of reaction is the above reaction? The elements in the REACTANTS are COMBINING with each other to become new molecules. Therefore a SYNTHESIS or ADDITION or BIOSYNTHESIS reaction is the result.

21. 2NaCl 2Na + Cl 2 What type of reaction is the above reaction? The elements in the REACTANTS are BREAKING DOWN from each other to become new molecules OR elements. Therefore a DECOMPOSITION reaction is the result.

22. CaCl 2 + F 2 CaF 2 + Cl 2 What type of reaction is the above reaction? The elements in the REACTANTS are switching with each other to become new molecules. Therefore a SINGLE REPLACEMENT reaction is the result.

23. AgNO 3 + KCl AgCl + KNO 3 What type of reaction is the above reaction? The elements in the REACTANTS are switching with each other to become new molecules. Therefore a DOUBLE REPLACEMENT reaction is the result.

24. N 2 + 3H 2 2NH 3 What type of reaction is the above reaction? The elements in the REACTANTS are COMBINING with each other to become new molecules. Therefore a SYNTHESIS or ADDITION or BIOSYNTHESIS reaction is the result.

25. 2H 2 O 2 2H 2 O + O 2 What type of reaction is the above reaction? The elements in the REACTANTS are BREAKING DOWN with each other to become new molecules. Therefore a DECOMPOSITION reaction is the result.

26. MgI 2 + Br 2 MgBr 2 + I 2 What type of reaction is the above reaction? The elements in the REACTANTS are switching with each other to become new molecules. Therefore a SINGLE REPLACEMENT reaction is the result.

27. SO 3 + H 2 O H 2 SO 4 What type of reaction is the above reaction? The elements in the REACTANTS are COMBINING with each other to become new molecules. Therefore a SYNTHESIS or ADDITION or BIOSYNTHESIS reaction is the result.

28. Atomic Structure: C 12 6 -4 A B C D What does each letter represent?