Final answer:
To determine the direction of change and equilibrium concentrations in a reaction, we need to consider the concentrations of the reactants and products, solve for 'x' using an ICE table, and check the math. Arrow D would be the best arrow to describe the equilibrium.
Step-by-step explanation:
In order to determine the direction of change in an equilibrium, we need to consider the concentrations of the reactants and products. If the concentration of the reactants is higher than the concentration of the products, the equilibrium will shift towards the products, and if the concentration of the products is higher, the equilibrium will shift towards the reactants.
To determine the equilibrium concentrations, we need to solve for the value of 'x' in the balanced reaction equation. This can be done using an ICE table, where we calculate the initial concentrations, change in concentrations, and equilibrium concentrations.
Once we have solved for 'x' and the equilibrium concentrations, it is important to check the math by plugging the calculated values back into the balanced reaction equation and ensuring that both sides of the equation are balanced.
Based on the given information, it seems that arrow D, labeled 'Check the math,' would be the best arrow to describe the equilibrium.