Which two gases can be used for the demonstration of the fountain experiment?

Which of the following pollutants will lead to the depletion of ozone layer?

Which of the following describes the chemical property of acids?

Which of the following pairs cannot be represented with a chemical formula?

Consider the equation below:

Cr\(_2\)O\(_7 ^{2-}\) + 6Fe\(^{2+}\) + 14H\(^{+}\) \(\to\) 2Cr\(^{3+}\) + 6Fe\(^{3+}\) + 7H\(_2\)O.

The oxidation number of chromium changes from