Question

Which best describes a compound such as sodium chloride?

O a pure substance that can be separated into different elements by physical means
O a mixture of two common substances that can be separated by chemical means
a mixture of two common elements that can be separated by physical means
a pure substance that can be separated into different elements by hemical means

Answer 1

Correct answer is the 4th option.
Sodium chloride, nacl is an ionic compound meaning that it is a pure substance. Hence, it likely on means it can only be separated by chemical means. For nacl, the only feasible way to obtain the pure elements is via electrolysis. In this case, nacl is the electrolyte and at the cathode and anode should be a inert electrode such as graphite or pt. Chlorine gas will then be released at the anode and sodium metal forms as a solid on the cathode during electrolysis. Yes, electrolysis is a chemical change not physical.