The coefficient should be 3 because 2(N)H3 has 6 hydrogen atoms and 3H2 also has 6 hydrogen atoms
Difference is in purity of reagents.
Ordinary reagent - reagents that can meet standard purity.
Analar reagent - chemical reagent of high purity with known contaminants for use in chemical analyses.
Industrial reagent - for <span>commercial and industrial purposes, not pure enough.</span>
Evaporation: process of a liquid changing to a gas.
precipitation: rain, snow, sleet, or hail that falls to the ground.
condensation: process of changing a gas to liquid.