An initial mixture of nitrogen gas and hydrogen gas is reacted in a rigid container at a certain temperature as follows: 3 h2(g) + n2(g) equilibrium reaction arrow 2 nh3(g). at equilibrium, the concentrations are [h2] = 5.6 m, [n2] = 9.3 m, and [nh3] = 5.1 m. what were the concentrations of nitrogen gas and hydrogen gas that were reacted initially?

[H₂] = 13 M

[N₂] = 12 M

Explanation:

Let´s consider the following reaction at equilibrium.

3 H₂(g) + N₂(g) ⇄ 2 NH₃(g)

To find out the initial concentrations we will use an ICE chart. We recognize 3 stages: Initial, Change and Equilibrium and complete each row with the concentration or change in concentration. We will use letters for the unknown data.

          3 H₂(g) + N₂(g) ⇄ 2 NH₃(g)

I              a           b                0

C          -3x         -x              +2x

E         a - 3x     b - x             2x

We know that,

[NH₃] = 2x = 5.1 M ⇒ x = 2.6 M

Then,

[H₂] = 5.6 M = a - 3x ⇒ a = 13 M

[N₂] = 9.3 M = b - x ⇒ b = 12 M

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.