26.7% is the percent composition by mass of sulfur in a compound named magnesium sulfate. Explanation: Molar mass of compound = 120 g/mol.
The given above pretty much states already that with the presence of the calcium carbonate which acts as the buffer will allow the solution to withstand changes in acidity. The greater the amount, the higher chances that it will be able to withstand the said changes. Therefore, if Lake X had greater ppm of CaCO3 then, it will be able to withstand greater amount of acid rain.
Carbon is the element at the heart of all organic compounds, and it is such a versatile element because of its ability to form straight chains, branched chains, and rings. Because these chains and rings can have all sorts of different functional groups in all sorts of different ways (giving the compond all sorts of different physical and chemical properties), carbon's ability to form the backbone of these large structures is critial to the existence of most chemical compounds known to man. Above all, the organic molecules crucial to the biochemical systems that govern living organisms depend on carbon compounds.