Before measuring the absorbance of a solution with the ocean optics spectrophotometer, it is important to run a blank sample of to correct for any light absorption not originating from the solute.

a. an empty cuvette
b. the solvent being used in the experiment
c. a standard solution
d. deionized water

b. The solvent being used in the experiment.

Explanation:

The spectrophotometer indicates the absorption of the light for the substance. So, during the experiment, is necessary to put the solvent first, so the equipment will discount the absorption of it, and then, with the samples, will indicate the absorption of the solute.

adding or remove a gaseous reactant or product changes the concentrations. if the concentration of reactant or product is increased, the system will shift away from the side in which concentration was increased (i.e. if the concentration of reactants is increased, the system will shift toward the products. if more products are added, the system will shift to form more reactants). conversely, if the concentration of reactant or product is decreased, the system will shift toward the side in which concentration was decreased (i.e. if reactants are removed, the system will shift to form more reactants. if the concentration of products is decreased, the equilibrium will shift toward the products).

explanation:

it is b that is the answer.