Question

Which of the following is a mixture?
1. Table Salt
2. Lime
3. ​Sea Water
4. Sugar

Answer 1

Correct Answer - Option 3 : ​Sea Water

The correct answer is ​Sea Water.

• Seawater is a complex mixture of 96.5 percent water, 2.5 percent salts, and smaller amounts of other substances, including dissolved inorganic and organic materials, particulates, and a few atmospheric gases.
• The density of seawater is a function of temperature, salinity, and pressure. 
• At a temperature of 4° C pure water reaches its maximum or peak density, cooled further it expands and becomes less dense than the surrounding water which is why when water freezes at 0° C it floats.
• Salinity and density share a positive relationship. As density increases, the number of salts in the water—also known as salinity, increases. Various events can contribute to change in the density of seawater.

• Salinity can decrease from the melting of polar ice or increase from the freezing of polar ice. Evaporation increases salinity and density while the addition of freshwater decreases salinity and density.