Help would be appreciated Consider the decomposition of Nitrogen Monoxide into its elements:

2NO(g) --> N2(g) + O2(g)

The reaction is endothermic with ΔH equal to -182.6kJ

The reaction is exothermic with ΔH equal to +182.6kJ

The reaction is exothermic with ΔH equal to -182.6kJ

The reaction is endothermic with ΔH equal to +182.6kJ

In a sample of oxygen gas at room temperature, the average kinetic energy of all the balls stays constant. which postulate of kinetic molecular theory best explains how this is possible? a. attractive forces between gas particles are negligible because the particles of an ideal gas are moving so quickly. b. collisions between gas particles are elastic; there is no net gain or loss of kinetic energy. c. gases consist of a large number of small particles, with a lot of space between the particles. d. gas particles are in constant, random motion, and higher kinetic energy means faster movement.

Which of the following is an indication that a substance has undergone a chemical change? a. no new product has been formed. b. the color of the substance has not changed. c. the original constitute has not changed. d. the molecular structure has changed.

How many grams of phosphorus are contained in 5.09 moles of phosphorus?