Which of the following reactions represents a precipitation reaction? 6H2O(l) + 6CO2(g) → C6H1206(1) + 6O2(g)
2C2H6(g) + 702(g) + 6H2O(g) + CO2(g)
O HCl(aq) + KOH(aq) → H2O(l) + KCl(aq)
CaCl2(aq) + Na2CO3(aq) → CaCO3(s) + 2NaCl(aq)

Write a paragraph that provides examples of each stage of volcanic activity, a description of the volcano, and facts about each stage.

Describe the forces both attractive and repulsive that occur as two atoms move closer together.

Nitric acid can be formed in two steps from the atmospheric gases nitrogen and oxygen, plus hydrogen prepared by reforming natural gas. in the first step, nitrogen and hydrogen react to form ammonia: (g) (g) (g) in the second step, ammonia and oxygen react to form nitric acid and water: (g) (g) (g) (g) calculate the net change in enthalpy for the formation of one mole of nitric acid from nitrogen, hydrogen and oxygen from these reactions. round your answer to the nearest .