A true statement about mass is that A. as the force of Earth's gravity on an object increases the object's mass increases.
B. mass is expressed in pounds
C. mass if often measured with a spring scale. D. mass is determined by comparing the mass of an object with a set of standard masses tha catalanse

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.