standard solution errors and improvements

Question 1

standard solution errors

Answer 1

If using anhydrous sodium hydrogensulfate (NaHSO4
), make sure it is not too old as it will have picked up water and therefore mass
values will not be as accurate.

Balance – usually gives to 0.01g (systematic error - same for each value that is recorded).

Alternatively the known mass of solid in the weighing bottle could be transferred to beaker, washed and washings added to the beaker.

Remember to fill so the bottom of the meniscus sits on the line on the neck of the flask. With dark liquids like potassium manganate
(K2MnO4
) it can be difficult to see the meniscus, so placing a piece of white paper behind to make the marker clearer to see.

Question 2

Reducing uncertainties in measuring mass:

Answer 2

Using a more accurate balance or a larger mass will reduce the uncertainty in weighing a solid.

Weighing sample before and after addition and then calculating difference (weighing by difference) will ensure a more accurate
measurement of the mass added.