Salinity Recovery

Which of the following statements are true? (Select ALL that apply)

• Saltwater is more dense that freshwater

• Freshwater is more dense than saltwater

• Freshwater layers below freshwater because water (H₂0) has more mass than salt (NaCl)

• Saltwater layers below freshwater because the salt molecule (NaCl) has more mass than the water molecule (H₂0)

Answer explanation

Saltwater is denser than freshwater due to the presence of dissolved salts, which increases its mass. Therefore, saltwater layers below freshwater, making the statement about salt's mass compared to water true.

What is the scientific name for salt? 

• Sodium Acetate 

• Sodium Chloride 

• Chloride sodium 

• Hydroxide sulfate 

Answer explanation

The scientific name for salt is Sodium Chloride (NaCl), which is composed of sodium and chloride ions. The other options do not represent common salt, making Sodium Chloride the correct choice.

The amount of salt found in water is -

• temperature

• salinity

• pollution

• clarity

Answer explanation

The amount of salt in water is referred to as salinity. It measures the concentration of salts, making salinity the correct choice over temperature, pollution, or clarity.

What is salinity?

• the amount of matter in a specific volume

• the degree of how hot or cold something is

• the landforms of the continent or the oceans

• how much salt is dissolved in a liquid

Answer explanation

Salinity specifically refers to how much salt is dissolved in a liquid, particularly in water. This distinguishes it from other concepts like temperature or landforms, making it the correct choice.

Which are examples of increasing salinity?

• Precipitation into the ocean

• Evaporation of water from the ocean

• Mouth of a river dumping freshwater into an ocean

• Glacier melting into an ocean

• Surface water freezing at the poles

Answer explanation

Evaporation of water increases salinity as it removes water but leaves salts behind. Similarly, surface water freezing at the poles concentrates salts in the remaining liquid, both leading to higher salinity.

Which are examples of decreasing salinity?

• Precipitation into the ocean

• Evaporation of water from the ocean

• Mouth of a river dumping freshwater into an ocean

• Glacier melting into an ocean

• Surface water freezing at the poles

Answer explanation

Decreasing salinity occurs when freshwater is added to the ocean. Precipitation, river mouths, and glacier melt introduce freshwater, reducing salinity. Evaporation increases salinity, and freezing at the poles does not decrease it.