In Cr2O3, the oxidation state of chromium can be determined by considering the overall charge of the compound and the oxidation state of oxygen. The compound Cr2O3 is neutral, meaning the overall charge is 0. Oxygen typically has an oxidation state of -2. Since there are three oxygen atoms in the compound, the total negative charge contributed by oxygen is -6.Now, let's consider the chromium atoms. There are two chromium atoms, and we'll represent their oxidation state as x. The sum of the oxidation states of all atoms in the compound should equal the overall charge of the compound, which is 0 in this case.So, the equation will be:2x + -6 = 0Solving for x:2x = 6x = 3Therefore, the oxidation state of chromium in Cr2O3 is +3.