Question

Anna, Anh and Amir are each given a sample of an unknown polymer and asked to calculate the density of their sample by measuring the mass and volume to determine if it could be polyaniline. They find a published value for the density of polyaniline to be 1.33 g cm^-3.

Amir quotes his final experimental value of the density of his sample with its uncertainty to be 1.36 ± 0.01 g cm^-3.

Select as many of the following statements that would be supported by Amir’s result.

		The sample may be polyaniline, but contains other substances which are ONLY less dense than polyaniline.
		The sample is polyaniline.
		The sample may be polyaniline, but the uncertainty has been underestimated.
		The published value for the density of polyaniline is incorrect.
		The equipment used to measure the volume is not precise enough to determine whether or not the sample is polyaniline.
		The equipment used to measure the volume is inaccurate.
		The sample is not polyaniline.
		The equipment used to measure the mass is not precise enough to determine whether or not the sample is polyaniline.
		The equipment used to measure the mass is inaccurate.
		The measurements are not precise enough to determine whether or not the sample is polyaniline.
		The sample may be polyaniline, but contains other substances which are ONLY more dense than polyaniline.
		The sample may be polyaniline, but a systematic error may be present in the technique.
		The equipment used to make the measurements are inaccurate.
		The sample may be polyaniline, but contains some other substances which are less dense than polyaniline.
		The sample may be polyaniline, but contains some other substances which are more dense than polyaniline.
		The measurements are precise enough to determine whether or not the sample is polyaniline.

Answer 1

The options to be selected are:

The measurements are not precise enough to determine whether or not the sample is polyaniline.

The equipment used to measure the volume is not precise enough to determine whether or not the sample is polyaniline.

The equipment used to measure the mass is not precise enough to determine whether or not the sample is polyaniline.

The sample may be polyaniline, but a systematic error may be present in the technique.

The equipment used to measure the volume is inaccurate.

The sample is polyaniline.

The sample may be polyaniline, but contains other substances which are ONLY more dense than polyaniline.

The equipment used to measure the mass is inaccurate.

The sample may be polyaniline, but contains some other substances which are more dense than polyaniline.

The equipment used to make the measurements are inaccurate.

The sample may be polyaniline, but the uncertainty has been underestimated.