Scenario: You are given with a bottle of best selling iron supplement tablet called UNITION, manufactured by Unity Factory in Singapore. In its advertisment, UNITION brands itself as the 'best' iron supplement tablet in the market as it is the only brand with such high amount of iron (3.5g of element iron in each tablet as stated in its ingredient list). Your Task: You are to plan and design an experiment to determine if the mass of iron present in one tablet of UNITION Brand compares well with the mass as stated by the manufacturer.

Sure, here's a step-by-step guide to design an experiment to determine the mass of iron in a UNITION tablet:

1. Materials Needed: UNITION iron supplement tablets, a highly sensitive digital scale, a beaker, distilled water, a magnetic stirrer, a filter paper, a funnel, a drying oven, and a spectrophotometer.

2. Weigh the Tablet: Use the digital scale to measure the mass of a UNITION tablet. Record this initial mass.

3. Dissolve the Tablet: Place the tablet in a beaker filled with distilled water. Use the magnetic stirrer to dissolve the tablet completely.

4. Filter the Solution: Once the tablet is fully dissolved, filter the solution using the filter paper and funnel to remove any insoluble materials.

5. Dry the Filter Paper: Place the filter paper in a drying oven until it's completely dry. This will ensure that only the iron from the tablet remains on the filter paper.

6. Weigh the Filter Paper: After drying, weigh the filter paper with the iron residue. Subtract the weight of the filter paper alone to find the mass of the iron.

7. Spectrophotometric Analysis: To confirm the mass of iron, perform a spectrophotometric analysis. This involves treating the iron with a specific reagent that forms a colored complex with iron. The intensity of the color, measured using a spectrophotometer, is directly proportional to the iron concentration.

8. Compare the Results: Compare the mass of iron obtained from the experiment with the mass stated by the manufacturer. If the values are close, then the manufacturer's claim is accurate.

Remember to perform this experiment multiple times to ensure the accuracy and reliability of the results.