Self Test for Unit 6: Chemical Reactions and Stoichiometry

Part 1: Multiple Choice with explanation:

  1. In the chemical equation  2H2O2(aq)      à  2H2O(l)  +  O2(g), the H2O2 is a:            (a) reactant.  (b) catalyst.  (c) product.  (d) spectator ion.
     

  2. The reaction in question 1 is an example of:  (a) double-replacement reaction           (b) single-replacement reaction  (c) decomposition reaction  (d) combination reaction
     

  3. The reaction, SrCl2(aq) +  NaOH(aq)  à  Sr(OH)2(s) +  NaCl(aq), is an example of:  (a) double-replacement reaction   (b) single-replacement reaction  (c) decomposition reaction  (d) combination reaction
     

  4. Which binary compound decomposes to form Ca  +  I2?  (a) CaI2  (b) CaI  (c) Ca2I  (d) none of these
     

  5. In order for the reaction  Cu(s)  +  2AgNO3(aq)  à  Cu(NO3)2(aq)  +  2Ag(s) to occur, which of the following must be true?  (a) Cu must be above Ag on the activity series.  (b) Ag must be above Cu on the activity series.  (c) Cu must be above H in the activity series.  (d) H must be above Cu in the activity series.
     

  6. Among the elements listed, which metal as an ion could be replaced by all of the rest of the metals?     (a) Cu  (b) Ca  (c) Fe  (d) Ag
     

  7. Based on the activity series, the reaction that is most likely to occur from among the following is:  (a) Ca(s)  +  CuCl2(aq) à  (b) Ag(s)  +  HCl(aq) à  (c) Mg(s)  +  Li2SO4(aq) à       (d) Hg(l)  +  Ca(NO3)2(aq) à
     

  8. Which of the following is a correct interpretation of this balanced equation?   2 Al(s)  +  3 Pb(NO3)2(aq) à  2 Al(NO3)3 (aq)  +  3Pb(s)

a)  2 grams Al + 3 grams Pb(NO3)2 à 2 grams Al(NO3)3  + 3 grams Pb 

b)  2 atoms Al + 3 units Pb(NO3)2 à 2 units Al(NO3)3  + 3 atoms Pb

c)  2 moles Al + 3 moles Pb(NO3)2 à 2 moles Al(NO3)3  + 3 moles Pb

d)  both b and c

9.      Given the equation  2H2O  à  2H2  +  O2, how many moles of H2O would be required to produce 2.5 moles of O2?  (a) 2.0 mol  (b) 2.5 mol  (c) 4.0 mol (d) 5.0 mol

10.  Given the balanced equation 16HCl  + 2KMnO4 à 2KCl  + 2MnCl2  +  5Cl2 + 8H2O, if 1.0 mol of KMnO4 reacts, how many moles of H2O are produced?  (a) 0.50 mol   (b) 2.0 mol  (c) 4.0 mol  (d) 8.0 mol

11.  Given the reaction 2NO(g) + O2(g) à 2NO2(g), if 13 L of O2 react at STP, how many liters of NO2 are produced?  (a) 6.5 L  (b) 3.2 L  (c) 26 L  (d) 13 L

12.  Given the reaction Zn + 2HCl à ZnCl2 + H2, if 2.0 mol Zn and 5.0 mol HCl are allowed to react:  (a) Zn is the limiting reagent.  (b) HCl is the limiting reagent.       (c) 1.0 mol of ZnCl2 is produced.  (d) 1.0 mol of H2 is produced.

Part 2: Problems – Solve the following problems in the space provided.  Remember to develop a system of showing your work, especially if you choose not to follow the problem solving method presented in class, your partial credit depends on this.

  1. Balance the following equations.  Tell what type of reaction each represents.

a.         Zn     +     HCl    à   H2(g)  +   ZnCl2

b.         AgNO3   +   AlI3   à   AgI(s)   +   Al(NO3)3

c.         Al2O3  à   Al   +   O2(g)

d.         C4H10   +   O2   à   CO2(g)   +   H2O(g)

e.         Fe   +   Br2   à   FeBr3

f.          Na2SO3   +   H2SO4   à   Na2SO4   +   H2O   +   SO2(g)

  1. Complete and balance the following equation.  What must be true of one of the products?

Li3PO4   +   Zn(NO3)2   à

  1. Balance the following equations.

(a)        FeCl3(aq)   +    NaOH(aq)   à    Fe(OH)3(s)   +   NaCl(aq)

(b)        HCl(aq)  +     CaCO3(aq)   à    CaCl2(aq)   +   H2O(l)   +     CO2(g)

(c)        Al2O3(s)  +    H2O(l)  à    Al(OH)3(s)

  1. Complete the following equations and balance them.

(a)        C6H14(g)  +     O2(g)  à

(b)        NCl3(s)  à

(c)        Zn(s)  +      FeCl3(aq)   à
                     (reaction does occur)

5.  2C4H10(g)  +  13O2(g)  à  8CO2  +  10H2O(g)  Answer the following questions based on this reaction.

a.         How many liters of oxygen (at STP) are required to burn 4.84 grams of butane (C4H10) completely?

b.         How many grams of CO2 are produced when 88.6g of O2 are reacted with an excess of butane?

6.         How many molecules of chlorine are produced when 40.0g of salt are split by electrolysis according to this equation?

2NaCl(s)      à  2Na(s)  +   Cl2(g)

7.         If 200.0g sample of Al is reacted with 175.0 L of O2 at STP according to the reaction: 4Al(s)  +  3O2(g)  à  2Al2O3(s), what is the maximum amount of product that can be formed?

  1. In problem #7 what is the limiting reactant?

 CHECK YOUR ANSWERS