Oxidation number of rubidium in `Rb_2O,Rb_2O_2 and RbO_2` , can be given respectively , as

Options

A. `+1,+4 and +2`
B. `+2,+1 and +1/2`
C. `+1,+1, and +1`
D. `+1,+2 and +4`

Answer

To determine the oxidation number of rubidium (Rb) in the compounds Rb₂O, Rb₂O₂, and RbO₂, we can follow these steps:

### Step 1: Understand the Oxidation States of Oxygen
- In most compounds, oxygen typically has an oxidation state of -2. However, in peroxides, it has an oxidation state of -1, and in superoxides, it has an oxidation state of -1/2.

### Step 2: Analyze Rb₂O
- For Rb₂O:
- Let the oxidation state of Rb be \( x \).
- The formula can be set up as follows:
\[ 2x + (-2) = 0 \]
- Solving for \( x \):
\[ 2x = 2 \\ x = +1 \]
- Therefore, the oxidation number of rubidium in Rb₂O is +1.

### Step 3: Analyze Rb₂O₂
- For Rb₂O₂ (a peroxide):
- The oxidation state of oxygen here is -1.
- Set up the equation:
\[ 2x + 2(-1) = 0 \]
- Solving for \( x \):
\[ 2x - 2 = 0 \\ 2x = 2 \\ x = +1 \]
- Therefore, the oxidation number of rubidium in Rb₂O₂ is also +1.

### Step 4: Analyze RbO₂
- For RbO₂ (a superoxide):
- The oxidation state of oxygen in superoxides is -1/2.
- Set up the equation:
\[ x + 2(-\frac{1}{2}) = 0 \]
- Solving for \( x \):
\[ x - 1 = 0 \\ x = +1 \]
- Therefore, the oxidation number of rubidium in RbO₂ is +1.

### Conclusion
- The oxidation numbers of rubidium in Rb₂O, Rb₂O₂, and RbO₂ are all +1.

### Final Answer
- The oxidation numbers of rubidium in Rb₂O, Rb₂O₂, and RbO₂ are respectively: **+1, +1, +1**.