Question

In the following reaction, describe what is likely to happen

CaSiO3 + H2CO3 <==> CaCO3 + SiO2 + H₂O + Heat

	1.	CaSiO3and H2CO3 will increase until a new equilibrium is reached
	2.	CaCO3 + SiO2 will increase until a new equilibrium is reached
	3.	There will be no change in reactants
	4.	CaSiO3 + H2CO3 will eventual be completely lost
	5.	CaCO3 + SiO2 will eventually be completely lost

Entropy is the concept of the universe moving towards chaos! Dramatic, yes? We can also think of entropy as a system moving from order to disorder. Which of these is an example of a system moving from disorder to order?

	1.	The sun dying and turning into a black hole
	2.	Protein synthesis
	3.	The catalysis of glucose to drive cellular respiration
	4.	Photosynthesis converting carbon dioxide to glucose
	5.	None of the above. You cannot reverse entropy.

The majority of nitrogen on this planet is in the form of nitrogen gas (N2), however cellular metabolism demands nitrate! Why is N2 not converted to NO3- faster?  

	1.	N2 has a very large activation energy; thus, it is exceedingly difficult to generate nitrate. In fact, only a few organisms can break down N2!
		2. Nitrogen gas is preferred by several key organisms that ecologically important. They need it in rich supply in order to carry on more important ecological roles in the environment!
		3. Nitrite is actually the most common form of nitrogen on the planet.
	4.	None of the above. The TA is crazy.

Answer 1

3. Nitrite is cactually the most common from of nitrogen on the planet.

This is because we need NH4+ to react with NO2- to form N2.

NH+4 + NO−2 ===> N₂ + 2H₂O (ΔG° = -357 kJ mol-1)