16. What is the density of iron if 28.5g of iron is added to a graduated cylinder containing 45.5mL of water, causing the water level to rise to the 49.1mL mark?
Answer: B
The density of iron is 7.92 g/mL.
To find the density of iron, we first determine the volume of iron added to the water. The rise in water level is from 45.5 mL to 49.1 mL, indicating that the volume of iron is 49.1 mL - 45.5 mL = 3.6 mL. The density is then calculated using the formula density = mass/volume, which results in 28.5 g / 3.6 mL = 7.92 g/mL.
A) 0.63 g/mL
This option is incorrect because the calculated density of iron (7.92 g/mL) is significantly higher than 0.63 g/mL. Such a low density does not correspond to iron, which is known to have a much greater density.
B) 7.92 g/mL
This option is correct as it accurately represents the calculated density of the iron sample. The mass of iron is 28.5 g, and the volume it occupies, determined from the water displacement method, is 3.6 mL. Therefore, the density is indeed 7.92 g/mL.
C) 0.58 g/mL
This option is also incorrect because it underestimates the density of iron. Based on the calculations, the density of 0.58 g/mL does not align with the known properties of iron and the specific values derived from the experiment.
D) None of the above.
This option is incorrect as well since option B provides the correct density of iron. The statement "None of the above" would only be valid if no correct options were available, but option B is accurate.
Conclusion
The correct answer is 7.92 g/mL, as it aligns perfectly with the calculated density based on the mass and volume of the iron added to the water. All other options fail to reflect the accurate density of iron, either by being too low or by incorrectly stating that no correct answer exists. Thus, option B is definitively the correct choice.