Copper mass = 1.659
Copper moles = 1.659 / 64 = 0.0259
Sulfur mass = 2.08 - 1.659 = 0.421
Sulfur moles = 0.421 / 32 = 0.0131
Ratio Copper : Sulfur = 2 : 1
Empirical formula: Cu ₂ S
Name: Copper (I) sulfide
Considering that scientific notation has to move the decimal over so there is only one digit in the Tens place, that is the scientific notation.
A density of the substance is an intrinsic property. Each substance has its own value of density, and it is constant. Since density is equal to mass over volume, a graph of mass vs volume would have a constant slope equal to density. So, it will be a linear graph. The mass is in the y-axis, and the volume is on the x-axis. Locate V = 16 mL on the x-axis, project it upwards until it intersects with the linear graph, then, move towards the left to determine the corresponding y-value, represented by the mass.
