1. balance equations:----> (equals heat )
NaNO3 ----> NaNO2 + O2
SiO2 -----> no reaction
PbO2 -----> PbO + O2
MgO -------> no reaction
KClO3 -----> KCl + O2
2 .Rocks and soil on the Moon, as on the Earth, consist mainly of silicon-oxygen compounds, called silicates. What is the chance that astronauts could easily obtain oxygen on the Moon by heating the rock and soil there? Why? Hint: Silicates are chemically similar to the silicon dioxide used in Part I of this experiment.
my attempt :
The experiment we did in lab was silicon dioxide heated and there was no reaction. silicon dioxide particularly stable and doesnt decompose, even under intense heat of a bunsen burner.
4.How many grams of oxygen gas (O2) are formed by the complete decomposition of 7.0 g of KClO3? Use the balanced equation for KClO3 from Part 1 to perform this calculation.
5. If 2.55 g of S8 react with excess oxygen gas (O2) how many grams of sulfur dioxide gas (SO2) will be formed?
6. If 1.115 g of phsphorus (P4) reacts with excess oxygen gas (O2) how many grams of tetraphosphorus pentaoxide (P4O10) will be produced?
7. If 2.660 g of magnesium metal reacts with 1.555 g of oxygen gas (O2) how many grams of magnesium oxide (MgO) will be produced?
8. Explain any differences between the amount of oxygen that was produced from the decomposition of potassium chlorate and the amount of oxygen collected (question 3 and question 4). Which is greater and why?
9. The products of the reactions of sulfur, phosphorus, and magnesium with oxygen are shown on the data sheet. Write the equations for the reactions of each of those products with water and explain whether the solution should be acidic or basic. Then compare your experimental results with your predictions. Are they the same? Explain.
Reaction with oxygen universal indicator phenolphalein indicator
Sulfur red acid nr
Phosphorous red acid nr
Magnesium blue base pink base
10. What can you conclude about the acidity of exhaled breath. Propose a hypothesis to explain the acidity of exhale breath.
Manganese dioxide was added to the potassium chlorate in Part 2 to speed up the reaction. A catalyst is a chemical species that speeds up a reaction without being consumed in the process. Consider the physical properties of manganese dioxide in this experiment, before and after the reaction, in Part 2. Based on your observations, is manganese dioxide a catalyst? Explain.
12. Use the ideal gas law (PV = nRT) to determine the number of liters of O2, measured at 25°C and 1.0 atmosphere, formed from the 7.0 grams of KClO3 ?
P = pressure of the gas in the units of atm
V = gas volume in the units of liters
n = number of moles of the gas
TK = gas temperature in Kelvin ( TK = T°C + 273),R =0.08206 L×atm
13. How many liters of oxygen did you actually collected in this experiment?
volume of 1 collection bottle was 240 mL
total volume of oxygen collected was 720 mL
This solution explains a variety of problems dealign with oxygen containing compounds.