Answer:

Explanation:
Given :
Mass of a bar of lead = 115.2 g
Initial water level
= 25 mL
Final water level
= 35.5 mL
Difference in the water level = 35.5 - 25
= 10.5 mL
= 
We know that when a body is submerged in water, it displaces its own volume of water.
Therefore, the volume of the lead bar = volume of the water displaced = 10.5 mL = 
We know that mathematically, density is the ratio of mass of body to its volume.
Density of the lead bar is given by :


= 
Answer:
387 g/mol
Explanation:
The molar mass is a ratio comparing a substance's mass and molar value. The specific ratio looks like this:
Molar Mass (g/mol) = mass (g) / moles
You can plug the given values into the ratio to find the molar mass.
Molar Mass = mass / moles
Molar Mass = 0.406 g / 0.00105 mol
Molar Mass = 387 g/mol
6.02×[10]1 ×64.8=3900.96 moles