When sodium carbonate is dissolved in water, it doesn't dissociate, or break up, completely. There is always some sodium carbonate in solution. Knowing this, which of the two samples is most alkaline? Explain why you say this.

Question

anonymous · Answer

In real-life situations, workers collect water samples in a lake or stream instead of using Samples A and B. For this lab to work, sodium carbonate was added to make the water samples alkaline. In lakes and streams it is calcium carbonate (CaCO3) that causes alkalinity. Calcium carbonate acts as a buffer, a substance that serves to resist small changes in acidity or alkalinity in a solution. When acid rain enters lake water, it can be neutralized by the bases present and thus the lake does not become too acidic. Since the key ion is the hydroxide ion, the nature of the cation doesn't matter in this case. Right now, pollution workers are measuring calcium carbonate in lakes and streams. If a worker studied two lakes and Lake X had a greater ppm of calcium carbonate than Lake Z, which of the two lakes would be able to withstand a greater amount of acid rain? Explain your answer.