C. Thermosphere is the correct answer
In your choices, the best answer is the mass of the reactants and the mass of the products are no equal. The chemical equilibrium can take place in a close system and can not be affected by catalyst and is a reversible reaction. The best describe should be the concentration of reactants and products are constant.
Decomposition is a chemical reaction that breaks the reactant into two or more products. Moles of nitrogen gas 
in the cylinder is 1.63 moles.
<h3>What is the ideal gas equation?</h3>
The ideal gas equation states the relation of the hypothetical ideal gas according to the pressure, volume, temperature and moles of the gas. It is given by,
Where,
Pressure (P) = 2000 kPa
Volume (V) = 2L
Temperature (T) = 295 K
Gas constant (R)= 0.08206
Substituting values in the equation:
Therefore, 1.63 moles are produced.
Learn more about ideal gas equation here:
brainly.com/question/26720901
D! It’s a pure substance and a compound
Magnesium chloride is the name for the chemical compounds with the formulas MgCl2 and its various hydrates MgCl2(H2O<span>)x. These salts are typical ionic halides, being highly soluble in water. The hydrated magnesium chloride can be extracted from brine or sea water.</span>
