Test Your Witts!!

The following are more example problems for you to work through. Try the problem, then watch the video for the solution. This is a good chance to see how others approach limiting reagent problems.
Problem #1:

4 NH3 + 5 O2 ----> 4 NO + 6 H2O

If 34 g of NH3 are reacted with 32 g of O2, how many g of NO are produced?




Problem #2:

H2 + O2 -----> H2O

What mass of water is formed when 2.30 g of hydrogen gas is reacted with 4.55 g of oxygen gas?
Problem #3:

3 Mn + 8 HNO3 ------> 3 Mn(NO3)2 + 2 NO + 3 H2O

How many g of NO are produced when 5.0 g of manganese are reacted with 10.0 g of nitric acid (HNO3)?

(NOTE: This problem ends at 4:10 on the video. The problem starting at 4:10 is a bit difficult for this class. If you skip to 7:40 on the video, there is a different method of figuring out what the excess reagent is.)
Problem #4:

P4 reacts with oxygen gas to produce diphosphorus pentoxide. If 8.00 g of P4 is reacted with 8.00 g of oxygen gas, how many grams of diphosphorus pentoxide are formed?

(Note the one minor error that the video makes while working the problem around the 4:21 mark....he should have used a 2:5 ratio. This final answer is still correct!)


Problem 5:

Al + Br2 ------> Al2Br6

If 3 mol of aluminum is reacted with 3 mol of bromine, which one is the limiting reagent?

(Note: The video does not get to this problem until the 6:19 mark. However, the beginning of this video is an excellent review of limiting reagent concepts.)


Last modified: Thursday, August 12, 2010, 9:46 AM