A research chemist wants to verify that an unknown elemental metal sample is magnesium
CHEMISTRY · Multi-part · A Level · Chemistry · Amount of substance · Amount of substance
Problem
A research chemist wants to verify that an unknown elemental metal sample is magnesium, which has an accepted molar mass of 24.3 g mol⁻¹. In a controlled experiment, she determines that a 4.86 g sample contains approximately 1.21 × 10²³ atoms.
Use the information provided to analyze whether the chemist’s experimental evidence is sufficient to confirm the identity of the metal.
(a) Describe the reasoning process you would follow to decide whether the unknown metal can be identified as magnesium based on the experimental data provided.
(b) Explain one major experimental source of uncertainty that could affect the accuracy of the chemist’s conclusion, and discuss how that uncertainty influences the final decision.
(c) Suggest one additional experimental measurement (other than repeating the same determination) that would strengthen the identification of the sample and justify why it would be effective.