Chemistry
Name______________________________________________
1. 2 H2O  2 H2 + O2
What type of reaction does this equation represent?
2. How does the balanced chemical equation in #1 show the Law of Conservation of Mass?
3. Cu(s) + AgNO3(aq) --> Cu(NO3)2(aq) + Ag(s). Balance the equation using the smallest whole – number
coefficients.
4. What is the oxidation number of carbon in H2CO3(aq)?
5. What is the chemical formula for tin(II) fluoride?
6. What is the correct formula for iron (II) phosphate?
7. What is the total number of electrons in a Cr3+ ion?
(1) 18
(2) 24
(3) 21
(4) 27
8. Given the reaction: Mg(s) + 2 AgNO3(aq) --> Mg(NO3)2(aq) + 2 Ag(s) Which type of reaction is represented?
(1) single replacement
(2) synthesis (3) double replacement
(4) decomposition
9. What is the proper chemical formula for copper (II) hydroxide?
10. Which compound contains both ionic and covalent bonds?
(1) CaCO3
(2) MgF2
(3) PCl3
(4) CH2O
11. Which equation shows a conservation of mass?
(1) Na + Cl2  NaCl
(3) Al + Br2  AlBr3
(2) H2O  H2 + O2
(4) PCl5  PCl3 + Cl2
12. Which substance has a chemical formula with the same ratio of metal ions to nonmetal ions as in potassium
sulfide?
(1) sodium oxide
(2) sodium chloride
(3) magnesium oxide (4) magnesium chloride
13. Draw the Lewis Structure for a molecule of chlorine, Cl2.
14. Explain in terms of electrons why the bonding in sodium chloride is ionic.
15. What type of reaction occurs when silver nitrate is reacted with sodium chloride?
16. Draw the Lewis Structure for a sulfide ion.
17. A binary compound consists of element X and chlorine in a 1:2 molar ratio. What is the oxidation number of
element X in this compound?
18. Explain, in terms of atomic structure, why liquid mercury is a good electrical conductor.
19. After a neutral sulfur atom gains two electrons, what is the resulting charge of the ion?
20. Which type of bond results when one or more valence electrons are transferred from one atom to another?
21. The chemical bonding in sodium phosphate, Na3PO4, is classified as
(1) ionic, only (2) metallic, only (3) both covalent and ionic (4) both covalent and metallic
22. During all chemical reactions, mass, energy, and charge are
(1) absorbed
(2) formed
(3) conserved
23. What is the oxidation number of sulfur in Na2S2O3?
(1) - 1
(2) +6
(3) +2
(4) released
(4) +4
24. A 4.86-gram sample of calcium reacted completely with oxygen to form 6.80 grams of calcium oxide.
This reaction is represented by the balanced equation below.
2Ca(s) + O2(g) --> 2CaO(s)
Determine the total mass of oxygen that reacted.
25. What is the chemical formula for iron(III) oxide?
(1) FeO
(2) Fe3O
(3) Fe2O3
(4) Fe3O2
26. Which equation shows conservation of mass and charge?
(1) NH4Br → NH3 + Br2
(3) H2SO4 + LiOH → Li2SO4 + H2O
(2) 2Mg + Fe3+ → Mg2+ + 3Fe
(4) Cu + 2Ag+ → Cu2+ + 2Ag
27. The unbalanced equation below represents the decomposition of potassium chlorate.
_____KClO3(s) _____ KCl(s) +_____ O2(g)
Balance the equation using the smallest whole-number coefficients.
Determine the oxidation number of chlorine in the reactant.
28. The particle diagrams below represent the reaction between two nonmetals, A2 and Q2.
KEY
● = Atom of element A
○ = Atom of element Q
○○
○○
●●
Reactants
○●○

○●○
Products
a) Using the symbols A and Q, write the chemical formula of the product.
b)
Identify the type of chemical bond between an atom of element A and an atom of element Q.
c)
Compare the total mass of the reactants to the total mass of the product.
29. A student places a 2.50-gram sample of magnesium metal in a bottle and fits the bottle with a 2-hole stopper.
Hydrochloric acid is added to the bottle, causing a reaction to occur. The gas that is emitted is collected and tested with a
burning splint. A popping noise is noted.
a) Write the balanced chemical equation for the reaction.
b) Identify the gas that was produced by the reaction.
c) Identify the type of reaction that is occurring in the reaction bottle.