B) Rb
C) Cl^{-}
D) Kr
Answer: +4
Explanation:
Firstly, we know that Oxygen should have an oxidation number of -2. This is because according to oxidation rules, Oxygen's number will always be -2 unless it is a part of a peroxide and then it will be -1 (ex: H2O2). UO2 is not a peroxide, so the regular rules will apply.
We also know that oxidation numbers in a molecule with no charge should add up to zero. There are two oxygen molecules which makes their total oxidation numbers equal to -4. Therefore, whatever U's oxidation number is should cancel out that -4 to make the total number 0.
So, U's oxidation number should be +4 since -4+4=0.
Answer:
d) Hydrogen chloride
Explanation:
Hydrogen chloride (HCl) is not a mixture. It is a chemical compound composed of two elements, hydrogen (H) and chlorine (Cl), combined in a fixed ratio. In contrast, the other options (antibiotic, evaporated milk, brewed coffee) all involve mixtures:
Antibiotics are typically mixtures of various chemical compounds used for medicinal purposes.
Evaporated milk is a mixture of milk and water with the water removed.
Brewed coffee is a mixture of water and coffee grounds, often with other components like sugar or cream added.
Hydrogen chloride, on the other hand, is a pure compound with a defined chemical formula (HCl) and consistent composition.
A.2
B.6
C.12
D.6
FALSE