the crucible is not fired, as the procedure suggests, but had retained some impurities from previous use(or it could be oily smudges from fingers). the mass of the "dirty" crucible is recorded. however the impurities are burned off in the experiment. how does this affect the reported mass of the final product? explain

What is your SCHOOL SUBJECT?

This must be a chemistry question and you gave VERY little evidence of what you are working on. However, in general, let's make up some numbers.

15.00 g = clean xble
17.00 g = xble + our ppt
----------
2.00 g = mass ppt.

BUT suppose the xble is dirty, as the problem suggests, so it actually weighs 16.00 g = mass clean xble + dirt
When we add the ppt to the dirty xble, we have
15.00 clean xble
1.00 g dirt
2.00 g ppt
-----
Total 18.00 g

Now we fire it, the dirt burns off and it will weigh
15.00 g for clean xble
+2.00 for ppt
Total is 17.00
and when we subtract 17.00-16.00 = 1.00 g ppt which of course is wrong. We actually had 2.00 g ppt; therefore, the mass of the reported material is too low.

When the impurities from the "dirty" crucible are burned off during the experiment, it will affect the reported mass of the final product.

When the crucible is not fired as the procedure suggests and contains impurities, the mass recorded will include not only the actual mass of the substance being measured but also the additional mass of the impurities. These impurities could be in the form of debris or oily smudges from fingers, causing the crucible to have a greater mass than intended.

However, during the experiment, when the crucible is heated or subjected to high temperatures, the impurities will burn off and get converted into byproducts such as gases or ashes. As a result, the mass of the impurities will be reduced or completely eliminated.

This means that the final product obtained after burning off the impurities will have a lesser mass than the recorded mass of the "dirty" crucible. Therefore, it is essential to account for the weight of the impurities or perform a correction factor to obtain the accurate mass of the final product.

When the crucible is not properly cleaned or still contains impurities from previous use, it adds extra mass to the "dirty" crucible. This extra mass includes any remaining residue, such as oils or other contaminants.

During the experiment, when the impurities are burned off, they are converted into gases and released into the atmosphere. As a result, these impurities no longer contribute to the mass of the crucible or the final product.

Therefore, when the final product is weighed after the impurities have been burned off, the reported mass will only consist of the desired substance or product that remains in the crucible.

To accurately determine the mass of the final product, it is important to subtract the initial mass of the "dirty" crucible from the mass of the crucible with the final product. This subtraction accounts for the mass of the impurities that were burned off during the experiment.