Sea water is unfit for drinking because it contain large amount of dissolved salts.... correct answer is D...

Why is sea water unfit for drinking?

The correct answer is option D, which states that sea water is unfit for drinking due to the large amount of salt it contains. Let's explore this in detail:

1. Salinity of sea water:
Sea water is composed mainly of water and dissolved salts. The salinity of seawater is approximately 3.5%, which means that for every 1 liter of sea water, there are about 35 grams of dissolved salts. This high salt content makes sea water unsuitable for drinking by humans.

2. Effect of excessive salt intake:
Drinking sea water can have negative effects on the human body. When we consume water with a high salt concentration, it upsets the delicate balance of electrolytes in our body. This can lead to dehydration, as the body tries to eliminate the excess salt through increased urine production. In severe cases, it can even lead to kidney damage and organ failure.

3. Osmosis and the body:
The human body needs water to survive, but it also needs water with the right concentration of dissolved substances. When we drink water, it is absorbed into our cells through a process called osmosis. Osmosis allows water to move from an area of lower solute concentration (inside the cells) to an area of higher solute concentration (outside the cells). Drinking sea water, with its high salt concentration, would reverse this process and dehydrate the cells instead of hydrating them.

4. Availability of fresh water:
Fortunately, sea water is not the only source of water on Earth. Freshwater sources such as rivers, lakes, and underground aquifers contain much lower levels of salt and are suitable for drinking. These sources can be treated and purified to remove any harmful substances, making the water safe for consumption.

In conclusion, sea water is unfit for drinking primarily due to its high salt content. Consuming sea water can lead to dehydration, electrolyte imbalances, and other health issues. It is essential to rely on freshwater sources that have lower levels of salt for our drinking water needs.