Nitrogen Extraction and Soil Testing

The video tutorial demonstrates a nitrogen test to detect nitrates in soil samples. It begins with preparing the nitrogen extraction solution and adding soil samples. After shaking and settling, the clear liquid is pipetted into a new test tube, where nitrogen indicator powder is added. The solution is shaken again, and the resulting color change is compared to a key to determine nitrogen levels. The crime scene sample shows a low nitrogen level, while the suspect sample indicates a high level.

What is the purpose of adding nitrogen extraction solution to the soil samples?

• To change the color of the soil

• To increase the soil's pH level

• To dissolve the soil

• To extract nitrogen from the soil

How much soil sample is added to the test tube with nitrogen extraction solution?

• Two scoops

• Half a scoop

• One scoop

• Three scoops

What is the next step after agitating the soil samples for one minute?

• Extracting the clear liquid

• Heating the solution

• Adding more soil

• Filtering the soil

How should the dropper be prepared before pipetting the clear liquid?

• Cool it

• Heat it

• Squeeze out all the air

• Fill it with air

To which line should the clear liquid be pipetted in the new test tube?

• Line 2

• Line 1

• Line 3

• Line 4

How many scoops of nitrogen indicator powder are added to the test tube?

• Four scoops

• Three scoops

• Two scoops

• One scoop

For how long should the test tube be shaken after adding the nitrogen indicator powder?

• One minute

• Two minutes

• Four minutes

• Three minutes

What color indicates a high level of nitrogen in the soil sample?

• Light pink

• No color

• Hot pink

• Medium pink

What does a light pink color in the crime scene sample indicate?

• High nitrogen level

• No nitrogen

• Low nitrogen level

• Medium nitrogen level

What should be done after recording the nitrogen levels on the data sheets?

• Continue with more chemical testing

• Repeat the test

• Dispose of the samples

• Store the samples