What is the mass of one mole of oxygen gas?

The diagram below shows the different phase transitions that occur in matter. which arrow represents the transition in which dew is formed?

Liquid ammonia is produced at high temperatures and under great pressure in a tank by passing a mixture of nitrogen gas and hydrogen gas over an iron catalyst. the reaction is represented by the following equation. n2(g) + 3h2(g) → 2nh3(g) changing all but one experimental condition will affect the amount of ammonia produced. that condition is a) increasing the concentration of both reactants b) changing the temperature within the tank c) decreasing the pressure within the tank. d) increasing only the amount of nitrogen present.

Concentrations expressed as a percent by mass are useful when the solute is a a. liquid b. gas c. solid