Precision of measurement

Materials:

Measuring Cylinder            

Pipette

Volumetric flask

NaCl (Common Salt)

Hexane

Procedure:

Test 1:

1.Get a an empty measuring cylinder.

2. Weight it, it had a total weight of 77.8 g.

3. Use the pipette and the measurement cylinder to put 10 ml of water.

4. Pour the water on the measuring cylinder.

5. Weight the total mass.

6. Subtract the mass of the measuring cylinder to the total and you will have the weight of the water. (9.43g)

Test 2:

1.       Use the same measuring cylinder (which weights 77.8g) to introduce 2,5 grams of NaCl (table salt).

2.       Weight it with the salt in it.

3.       Do the same equation in order to obtain the mass of the solution.

Conclusion:

We have seen how NaCl has dissolved in water but not in hexane, this is because NaCl and water are both polar substances so they can dissolve easily while hexane is a covalent bond and water, as we have said, is polar so it is very hard to make them dissolve.

By doing this work, we learnt how to accurate more our results and that, even if we with the higher accuracy possible, it wasn't perfect. For the next time I think that we could try to be more precise, take more notes and photos of absolutely all in order to have good images to explain the experiment.