Final answer:
D) decreasing the pH to slightly under 7 for a period of time. To control carbonate deposits from brine on ice cans, the recommended method is to decrease the pH to slightly under 7,
Step-by-step explanation:
To control carbonate deposits from brine on ice cans one effective method is by decreasing the pH to slightly under 7 for a period of time.
This practice is based on the principle that the concentration of anions in a solution can often be controlled by adjusting the pH, which allows for the selective precipitation of cations.
For example, calcium carbonate (CaCO3), which is quite insoluble, can be precipitated from calcium bicarbonate (Ca(HCO3)2) in hard water when CO2 is lost from the solution.
Adjusting the pH to a more acidic condition by adding a strong acid, such as hydrochloric acid (HCl), increases the concentration of hydrogen ions, leading to the formation of carbon dioxide from bicarbonate and the subsequent precipitation of calcium carbonate.
So, the correct answer to the question is (D) decreasing the pH to slightly under 7 for a period of time.
Carbonate deposits from brine on ice cans can be controlled to a great extent by decreasing the pH to slightly under 7 for a period of time.
This is because carbonate salts, such as calcium carbonate, are less soluble in acidic conditions. By lowering the pH, the solubility of carbonates decreases, resulting in the precipitation and removal of carbonate deposits.