Question

Salt concentration (Salinity) of the sea measured in parts per thousand is:

• A. 10 – 15
• B. 30 – 70
• C. 0 – 5
• D. 30 – 35

Answer 1

The correct option is D

30 – 35

On average, seawater in the world's oceans has a salinity of approximately 3.5%, or 35 parts per thousand. This means that for every 1 litre (1000 mL) of seawater there are 35 grams of salts, that is mostly sodium chloride and lesser quantities of other salts dissolved in it. In fresh water the concentration of salts, or salinity, is nearly zero. The mixture of seawater and fresh water in estuaries is called brackish water and its salinity can range from 0.5 to 35 ppt.