Salinity Experiment

Salinity Experiment

Aim

To determine a method of measuring a soil sample's salinity level in order to measure 3 samples' salinity level.

Hypothesis

I think that by running a current through a salt solution and measuring the resultant amperage, a pattern in the recordings will help find a soil sample's salinity level.

Variables

Controlled - Amount of solution (100 mL), supplied voltage (4V), amount of soil (50 gm) & water (150 mL) in soil sample's solution.

Independent - Amps recorded by ammeter.

Uncontrollable - Impurities dissolved into water.

Materials

Power pack; copper electrodes; ammeter; 8 different concentrations of salt solution (NaCl) - 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5 mols; beakers; filter papers; funnel; wires; retort stand; scales; 3 soil samples; distilled water.

Method

1) Pour 100 mL of 0.1 mol NaCl solution onto beaker, place electrodes in solution and run 4V through the circuit as shown in the following diagram

2) Record amperage from ammeter.

3) Repeat steps 1 & 2 for 0.5, 1, 1.5, 2, 2.5, 3, 3.5 mols NaCl solution.

4) Observe results for a pattern linking salt level and amperage.

5) Mix soil and water to dissolve salt from soil.

6) Filter mixture to remove soil.

7) Run current through sample as in step 1.

8) Record amperage.

9) Repeat steps 5-8