Balancing Equations and Stoichiometry

Chemistry 11 Test VII.1

Balancing Equations and Stoichiometry

1. Balance the following equations.

A. ___ NH3 + ___ O2 ® ___ N2 + ___ H2O

B. ___ Ca3(PO4)2 + ___ SiO2 + ___ C ® ___ CaSiO3 + ___ CO + ___ P4

C. ___ C9H18S + ___ O2 ® ___ CO2 + ___ H2O + ___ SO2

D. ___ CaSi2 + ___ SbCl3 ® ___ Si + ___ Sb + ___ CaCl2

E. ___ KMnO4 + ___ HBr ® ___ MnBr2 + ___ Br2 + ___ KBr + ___ H2O

2. Write and balance the following word equations.

A. chromium + oxygen ® chromium (III) oxide

B. magnesium + phosphorous ® magnesium phosphide

C. xenon hexafluoride + water ® xenon trioxide + hydrogen fluoride

D. calcium hydroxide + sodium phosphate ® sodium hydroxide + calcium phosphate

E. iron (III) oxide + carbon monoxide ® iron + carbon dioxide

3. Classify the following reactions.

A. 3HF + Fe(OH)3 ® FeF3 + 3H2O

B. Cl2 + KI ® I2 + KCl

C. 4Al + 3O2 ® 2Al2O3

D. C2H5OH + 3O2 —> 3H2O + 2CO2

E. 2H2O2 ® H2O + O2

F. 2Fe(NO3)3 + 3MgS ® Fe2S3 + 3Mg(NO3)2

4. Complete and balance the following equations.

A. ___ Zn + ___ Ni(NO3)2 ®

B. ___ C9H20O4S2 + ___ O2 ®

C. ___ NH3 ®

D. ___ Li + ___ O2 ®

E. ___ Mg + ___ S8 ®

F. ___ AlCl3 + ___ Na2CO3 ®

5. Consider the following balanced equation:

2C8H18S + 27O2 ® 16CO2 + 18H2O + 2SO2

A. How many moles of water are produced from the reaction of 135 moles of oxygen?

B. If 15 mole of C8H18S react, how many moles of carbon dioxide are formed?

C. How many moles of C8H18S must have reacted if 75 moles of water are produced?

6. Consider the following reaction:

K2Cr2O7(aq) + 14HCl(aq) ® 2KCl(aq) + 2CrCl3(aq) + 7H2O(l) + 3Cl2(g)

A. What mass of K2Cr2O7 is required to produce 75.0 g of H2O?

B. How many molecules of Cl2 are produced from the reaction of 100.0 g of HCl?

C. What volume of Cl2(g) is produced at STP from the reaction of 25.0 g of K2Cr2O7?

D. If the [HCl] is 0.750 M, what volume of HCl is required to produce 35.0 g of CrCl3?

7. A 25.00 mL sample of Fe2+ is titrated with 12.53 mL of 0.0500 M MnO4- according to the following balanced equation:

MnO4- + 8H+ + 5Fe2+ ® Mn2+ + 4H2O + 5Fe3+

What is the [Fe2+] in the original 25.00 mL sample?

Bonus Questions

___ Sn + ___ HNO3 ® ___ Sn(NO3)2 + ___ H2O + ___ NH4NO3

___ Cu + ___ HNO3 ® ___ Cu(NO3)2 + ___ NO + ___ H2O

___ KMnO4 + ___ HNO3 + ___ H2C2O4 ® ___ Mn(NO3)2 + ___ H2O + ___ CO2 + ___ KNO3

Balancing Equations and Stoichiometry 2