Question

All measurements contain errors. Averaging the measurements reduces the error. A graph can also reduce error when the line is drawn through the center of the data. A student measured the mass and volume of 5 different pieces of the same metal, plotted the data and obtained a slope of 8.90 g/mL. How did you know that the metal was copper and not nickel? (Describe a different way to identify that the metal is copper).

Answer 1

Answer:

See explanation

Explanation:

The slope of a graph in which mass was plotted against volume is the density of the object. Density of objects have been measured and recorded in standard handbooks for the purpose of reference. If the density of an unknown substance is measured, it can now be compared with the density of known substances recorded in standard handbooks such as the handbook of physics and chemistry. By so doing, the unknown substance can be identified.

According to standard handbooks, the density of copper is 8.96 g/ml while that of nickel is 8.908 g/ml. If the average slope obtained is around 8.96 g/ml, then the metal is copper and not nickel.

An alternative to this method is to measure the refractive index of the piece of metal and compare the average values observed with the contents of standard handbooks in order to identify the unknown metal.