Water Nuggets Practice Exam

When carbon dioxide (CO2) is introduced into water, it reacts to form carbonic acid (H2CO3). This process occurs when CO2 dissolves in water, leading to the following chemical equilibrium: CO2 + H2O ⇌ H2CO3 ⇌ HCO3- + H+ As carbonic acid dissociates, it releases hydrogen ions (H+) into the water, which causes an increase in acidity. A higher concentration of hydrogen ions in the solution results in a lower pH level, indicating a more acidic environment. Thus, the introduction of CO2 into water results in a decrease in pH levels. Other options such as an increase in pH would imply a reduction in acidity, which does not occur with the addition of CO2. Stability in pH levels suggests no effect from CO2, which contradicts the known reactions. Fluctuating pH levels would imply a constant change, which is not the typical immediate result of CO2 being introduced; rather, the pH will decrease steadily until a new equilibrium is achieved.