CHEM 3: Challenge Problem Set 5
1.
Consider the two observations below:

Aqueous potassium silicate (K2SiO3), when mixed with aqueous chromium (III) nitrate, generates a precipitate.

Aqueous sodium nitrate, when mixed with aqueous potassium chlorate, does NOT generate a precipitate.
Based solely on the results above, what is the most likely formula for the precipitate formed in the first reaction?
On your own: As practice for the next exam, try to write the balanced equation for this reaction.
2.
MARK ALL THAT APPLY: Which substances below are most likely to form insoluble precipitates in aqueous
solution?
CaSO4
Li3PO4
(NH4)2SO4
PbBr4
Sr(OH)2
Rb2CO3
BaS
3.
Nitroglycerine decomposes according to the reaction below:
4 C3H5(ONO2)3(l) ---> 6 N2(g) + O2(g) + 10 H2O(g) + 12 CO2(g)
If 8.0 moles of nitroglycerine undergoes complete decomposition, how many moles of gas (including all
products) could be generated?
4.
5.
Consider the complete combustion of stearic acid, a common fatty acid, with the formula C18H36O2.

If 10.5 moles of stearic acid is burned in an oxygen rich atmosphere, how many moles of oxygen gas (O 2)
must be consumed?

How many moles of carbon dioxide gas would be generated in the combustion above?
Consider the single replacement reaction between aluminum metal and copper (II) oxide.

If 6 moles of aluminum metal react with excess copper (II) oxide, what is the theoretical yield of copper
metal (in moles) that forms as a product?

How many moles of aluminum oxide would be generated as a by-product of this reaction starting from 6
moles of aluminum metal?
6. Consider the decomposition of nitrogen triiodide to generate the component elements (diatomic nitrogen &
diatomic iodine). If 5.00 grams of NI3 decompose, how many grams of iodine would be produced?