1. Unit 3 Chemical Reactions
Review Questions
You will need:
1. A periodic Table
2. Your cheat sheet, solubility / activity series sheet

2. Warm-Up Problem Identify the Reaction Type Silver + Chlorine 
Composition
Decomposition
Single Replacement
Double Replacement
Combustion

3. Warm-Up Problem Identify the Reaction Type C2H6 + oxygen  Composition
Decomposition
Single Replacement
Double Replacement
Combustion

4. Warm-Up Problem Identify the Reaction Type Ba(ClO3)2  Composition
Decomposition
Single Replacement
Double Replacement
Combustion

5. Warm-Up Problem Identify the Reaction Type Zn + PbS  Composition
Decomposition
Single Replacement
Double Replacement
Combustion

6. SR Rxn: -- since Mg is higher than H, it reacts
Tip: Use ‘nerdy name’ for hydrochloric acid
Reminder: Hydrogen is Diatomic, so formula is H2
hydrogen chloride + magnesium  magnesium chloride + hydrogen (g)
2HCl(aq) + Mg(s)  MgCl2(aq) + H2(g)
Problem #1
Which would be the result of combining hydrochloric acid with magnesium?
Nothing will happen
It will form a precipitate
It will bubble.
It will burst into flames.

7. 2HNO3(aq) + Na2S(aq)  2NaNO3(aq) + H2S(g)
DR Rxn: --
Tip: Use ‘nerdy name’ for nitric acid
Reminder: Hydrogen is not on your solubility table, so look at gases & liquids below it.
hydrogen nitrate(aq) + sodium sulfide  sodium nitrate(aq) + hydrogen sulfide (g)
2HNO3(aq) + Na2S(aq)  2NaNO3(aq) + H2S(g)
Problem #2
Which would be the result of reacting nitric acid (aq) with sodium sulfide (aq)?
Nothing will happen
It will form a precipitate
It will bubble.
It will burst into flames.

8. DR Rxn: --
Tip: Switch Partners and look for a precipitate, gas, or liquid
Reminder: When both ‘possible products’ are soluble, it is a “No Reaction”
lead chlorate(aq) + barium nitrate(aq)  lead nitrate(aq) + barium chlorate(aq)
Problem #3
Which would be the result of combining aqueous lead chlorate (aq) with barium nitrate? (aq)
I thought this would be exciting….
Nothing will happen
It will form a precipitate
It will bubble.
It will burst into flames.

9. Problem #4 Which would be the result of reacting C3H7OH with oxygen?
Combustion Rxn: --
Tip: Hydrocarbon + Oxygen is a combustion reaction
Reminder: A hydrocarbon will contain C, H, and sometimes O
Combustion reactions are extremely exothermic and the heat from them is used as our main source of energy
Problem #4
Which would be the result of reacting C3H7OH with oxygen?
Nothing will happen
It will form a precipitate
It will bubble.
It will give off much energy.

10. DR Rxn: --
Tip: Switch Partners and look for a precipitate, gas, or liquid
Reminder: When one of the ‘possible products’ in Insoluble, it will be a precipitate
In this case, the lead bromide will be a solid precipitate
lead chlorate(aq) + sodium bromide(aq)  lead bromide (s) + sodium chlorate(aq)
Problem #5
Which would be the result of combining aqueous lead chlorate (aq) with sodium bromide (aq)?
Nothing will happen
It will form a precipitate
It will bubble.
It will burst into flames.

11. Warm-Up Problem: Match the following
SrCl2 +K3PO4 
Zinc chloride + iodine 
C3H8 + O2 
Ba(HCO3)2 
Magnesium sulfite + nitric acid 
Needs energy to sustain the reaction
Results in nothing happening
Makes a precipitate
Makes bubbles
Very, very exothermic

12. Which one does not belong?
pH = 12.7
KOH
Phenolpthalein is colorless
Red litmus turns blue

13. Which one does not belong?
pH = 12.7
KOH
Phenolpthalein is colorless
Red litmus turns blue

14. Which one does not belong?
Reacts with metal
Blue Litmus turns red
Tastes sour
Does not conduct electricity

15. Which one does not belong?
Reacts with metal
Blue Litmus turns red
Tastes sour
Does not conduct electricity

16. Which rxn is NOT an acid/base rxn?
HCl + OH-  HOH + Cl-
NH Cl-  NH3 + HCl
Na2S + Pb(ClO3)2  PbS + 2NaClO3

17. Which rxn is NOT an acid/base rxn?
HCl + OH-  HOH + Cl-
NH Cl-  NH3 + HCl
Na2S + Pb(ClO3)2  PbS + 2NaClO3
Acids donate protons (H+’s)_, bases are proton acceptors
In both A and B, there is an H + that is being transferred. In C, there is no H+ that is being transferred

18. Which are Bases?
Ca(OH)2
HCl
ClO-
NaCl
NaOH

19. Which are Bases? Ca(OH)2 HCl ClO- (negative charge attracts proton)
NaCl
NaOH

20. True or False… Acid Rain..
Label A thru E on whiteboard and write True or False for each
True or False… Acid Rain..
Has a pH of less than 5.6
Is caused by volcanoes and lightning
Will burn your skin
Contains nitric and sulfuric acid
Is formed by a decomposition reaction

21. True or False… Acid Rain..
Has a pH of 5.6 or less -- True
Is caused by volcanoes and lightning –False – H2CO3 not main contributor
Will burn your skin -- False
Contains nitric and sulfuric acid -- True
Is formed by a decomposition reaction -- False (formed by Composition #5)

22. Write an equation showing the neutralization of acetic acid with magnesium hydroxide.

23. Write an equation showing the neutralization of acetic acid with magnesium hydroxide.
HC2H3O2(aq) + Mg(OH)2 (aq)  2H2O (l) + Mg(C2H3O2)2 (aq)

24. What causes acid rain?
Burning Fossil Fuels release NOx and SOx gases which combine chemically with the water in the air to make nitric and sulfuric acid.

25. Write an equation to show how each of the 2 acids in acid rain form.
NOx + H2O à HNO3
SOx + H2O à H2SO4

26. Explain how acid rain kills fish

27. Explain how acid rain harms plants (2 ways)

28. Why is concrete/limestone not the best choice for a monument or gravestone?
Concrete and Limestone are primarily made up of Calcium carbonate. CaCO3 is a base that reacts with acid, so the acid rain would react with these materials and slowly wear them away,