Which of the following best describes the transfer of fecal coliform and an impact on the environment? Fecal coliform increases the growth of algae in surface water bodies, killing fish.
Digestive problems in humans are elevated from the increase of fecal coliform into drinking water.
Fecal coliform decreases the amount of dissolved oxygen and an overpopulation of fish in surface water bodies occurs.
Fecal coliform increases the amount of organic substances in water and lowers the amount of dissolved oxygen, killing fish.

Fecal coliform increases the amount of organic substances in water and lowers the amount of dissolved oxygen, killing fish.

Explanation:

Fecal coliform are species of bacteria that are found in the intestine of warm-blooded animals like humans etc. Hence, they are released whenever they excrete feaces. Due to this reason, the presence of fecal coliform bacteria in a water body indicates fecal discharge into that water.

The presence of excessive fecal coliform in a water body increases the amount of organic substances in the water. These organic substances are decomposed by bacteria, which causes the oxygen present in the water body (dissolved oxygen) to deplete/decrease. The depletion of oxygen in the water threatens aerobic aquatic organisms e.g fishes and they ultimately suffocate and die.

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%

yes the answer is total mass in unchanged   : )