Question

Consider the statement: "Copper is a red-brown element obtained from copper sulfide ores by heating the ores in air, which forms copper oxide. Heating the copper oxide with carbon produces impure copper, which is purified by electrolysis." How many of these, I) color II) heating with carbon III) purification by electrolysis are physical properties or changes?

Answer 1

The heating with carbon process is a physical change, while the color change and purification process are chemical changes.

Step-by-step explanation:

Out of the three processes mentioned, only heating with carbon is a physical change. The change in color from red-brown to black when copper reacts with oxygen and forms copper oxide is a chemical change. Similarly, the purification of copper by electrolysis involves chemical reactions.

During heating with carbon, the copper oxide reacts with carbon to produce impure copper. This is a physical change because the composition and properties of the copper do not change. It is simply a change in physical state from a compound to an element.

On the other hand, the change in color and the purification process involve the rearrangement of atoms, resulting in the formation of different compounds or the separation of impurities. These changes are chemical in nature.

Answer 2

1, just I) color.

Step-by-step explanation:

Physical properties are the properties that can be observed without changing the composition of a substance, such as color, temperature, density, and boiling point.

A physical change is a change in the substance that only modifies its aggregation state, such as solidification, and boiling.

Chemical properties are the properties that need a reaction to being observed, such as the combustibility, which needs a combustion reaction to being quantified.

When a chemical reaction occurs, and the composition of the substance change, it's a chemical change.

So, the heating copper with carbon is a chemical reaction, and purification by electrolysis is too. Color is the only physical property.