Honors Chemistry Extra Stoichiometry Problems

1. Silver nitrate reacts with barium chloride to form silver chloride and barium nitrate.

a. Write and balance the chemical equation. 2 AgNO3 + BaCl2 ! 2 AgCl + Ba(NO3)2

b. If 39.02 grams of barium chloride are reacted in an excess of silver nitrate, how many representative particles (and what type) of silver chloride are produced?

39.02  𝑔  𝐵𝑎𝐶𝑙!1  𝑥  

1  𝑚𝑜𝑙𝑒  𝐵𝑎𝐶𝑙!208.233  𝑔  𝐵𝑎𝐶𝑙!

 𝑥  2  𝑚𝑜𝑙𝑒𝑠  𝐴𝑔𝐶𝑙1  𝑚𝑜𝑙𝑒  𝐵𝑎𝐶𝑙!

 𝑥  6.02  𝑥  10!"  𝑓.𝑢.𝐴𝑔𝐶𝑙

1  𝑚𝑜𝑙𝑒  𝐴𝑔𝐶𝑙 = 2.256  𝑥  10!"  𝑓.𝑢.𝐴𝑔𝐶𝑙

c. If 410.8 grams of barium nitrate are produced how many grams of silver nitrate were reacted?

410.8  𝑔  𝐵𝑎(𝑁𝑂!)!1  𝑥  

1  𝑚𝑜𝑙𝑒  𝐵𝑎(𝑁𝑂!)!261.335  𝑔  𝐵𝑎(𝑁𝑂!)!

 𝑥  2  𝑚𝑜𝑙𝑒𝑠  𝐴𝑔𝑁𝑂!1  𝑚𝑜𝑙𝑒  𝐵𝑎(𝑁𝑂!)!

 𝑥  169.872  𝑔  𝐴𝑔𝑁𝑂!1  𝑚𝑜𝑙𝑒  𝐴𝑔𝑁𝑂!

= 534.1  𝑔  𝐴𝑔𝑁𝑂!

2. Nitrogen gas is reacted with hydrogen gas to form nitrogen trihydride.

a. Write and balance the chemical equation. N2(g) + 3 H2(g) ! 2 NH3(g)

b. How many liters of nitrogen trihydride are produced at STP if 80.28 grams of hydrogen gas are reacted in an excess of nitrogen?

80.28  𝑔  𝐻!1  𝑥  

1  𝑚𝑜𝑙𝑒  𝐻!2.016  𝑔  𝐻!

 𝑥  2  𝑚𝑜𝑙𝑒𝑠  𝑁𝐻!3  𝑚𝑜𝑙𝑒𝑠  𝐻!

 𝑥  22.4  𝐿  𝑁𝐻!1  𝑚𝑜𝑙𝑒  𝑁𝐻!

= 594.7  𝐿  𝑁𝐻!

c. How many grams of hydrogen are needed to fully react 621.9 grams of nitrogen gas? 621.9  𝑔  𝑁!

1  𝑥  1  𝑚𝑜𝑙𝑒  𝑁!28.014  𝑔  𝑁!

 𝑥  3  𝑚𝑜𝑙𝑒𝑠  𝐻!1  𝑚𝑜𝑙𝑒  𝑁!

 𝑥  2.016  𝑔  𝐻!1  𝑚𝑜𝑙𝑒  𝐻!

= 134.3  𝑔  𝐻!

d. How many liters of nitrogen gas are needed to completely react 90.38 L of hydrogen gas at STP?

90.28  𝐿  𝐻!1  𝑥  

1  𝑚𝑜𝑙𝑒  𝐻!22.4  𝐿  𝐻!

 𝑥  1  𝑚𝑜𝑙𝑒  𝑁!3  𝑚𝑜𝑙𝑒  𝐻!

 𝑥  22.4  𝐿  𝑁!1  𝑚𝑜𝑙𝑒  𝑁!

= 30.09  𝐿  𝑁!  

OR

90.28  𝐿  𝐻!1  𝑥  

1  𝐿  𝑁!3  𝐿  𝐻!

= 30.09  𝐿  𝑁!

3. For the following problem, use the following chemical equation: C8H18(l) + O2(g) ! CO2(g) + H2O(g)

a. Balance the chemical equation. 2 C8H18(l) + 25 O2(g) ! 16 CO2(g) + 18 H2O(g)

b. How many moles of oxygen are needed to fully react 837.4 grams of C8H18? 837.4  𝑔  𝐶!𝐻!"

1  𝑥  1  𝑚𝑜𝑙𝑒  𝐶!𝐻!"

114.232  𝑔  𝐶!𝐻!"  𝑥  

25  𝑚𝑜𝑙𝑒𝑠  𝑂!2  𝑚𝑜𝑙𝑒𝑠  𝐶!𝐻!"

= 91.63  𝑚𝑜𝑙𝑒𝑠  𝑂!

c. How many liters of carbon dioxide gas are formed at STP when 3.829 x 1025 representative particles of C8H18 are reacted in an excess of oxygen gas?

3.829  𝑥  10!"  𝑚𝑜𝑙𝑒𝑐𝑢𝑙𝑒𝑠  𝐶!𝐻!"1

 𝑥  1  𝑚𝑜𝑙𝑒  𝐶!𝐻!"

6.02  𝑥  10!"  𝑚𝑜𝑙𝑒𝑐𝑢𝑙𝑒𝑠  𝐶!𝐻!"  𝑥  16  𝑚𝑜𝑙𝑒𝑠  𝐶𝑂!2  𝑚𝑜𝑙𝑒𝑠  𝐶!𝐻!"

 𝑥  22.4  𝐿  𝐶𝑂!1  𝑚𝑜𝑙𝑒  𝐶𝑂!

= 1.140  𝑥  10!  𝐿  𝐶𝑂!

d. How many grams of water are produced when 382.9 liters of oxygen gas at STP are fully reacted?

382.9  𝐿  𝑂!1  𝑥  

1  𝑚𝑜𝑙𝑒  𝑂!  22.4  𝐿  𝑂!

 𝑥  18  𝑚𝑜𝑙𝑒𝑠  𝐻!𝑂25  𝑚𝑜𝑙𝑒𝑠  𝑂!

 𝑥  18.015  𝑔  𝐻!𝑂1  𝑚𝑜𝑙𝑒𝑠  𝐻!𝑂

=  221.7  𝑔  𝐻!𝑂