Question

Determine the oxidation number of each atom in the following substances
NF3: N__ F__
K2CO3: K__ C__ O__
HlO4: H__ I__ O__
Br2: Br__
2Nal: Na__ l__
I2: I__
2NaBr: Na__ Br__
Fe2O3: Fe__ O__
2Al: Al__
Al2O3: Al__ O__
2Fe: Fe__

Answer 1

To determine the oxidation numbers of each atom in the given substances, we will follow standard rules for assigning oxidation states. Let's go through each substance one by one:

### NF3
- **N**: +3 (Nitrogen is less electronegative than fluorine)
- **F**: -1 (Fluorine always has an oxidation state of -1)

### K2CO3
- **K**: +1 (Potassium is an alkali metal, typically +1)
- **C**: +4 (In carbonate, C is typically +4)
- **O**: -2 (Oxygen usually has an oxidation state of -2)

### HIO4
- **H**: +1 (Hydrogen is usually +1)
- **I**: +7 (For Iodine in peroxides due to 4 O's, resulting in +7 total to balance for -8 from O)
- **O**: -2 (Oxygen usually has an oxidation state of -2)

### Br2
- **Br**: 0 (In elemental form, the oxidation state is 0)

### 2NaI
- **Na**: +1 (Sodium is an alkali metal, usually +1)
- **I**: -1 (Iodine in compounds is often -1, especially in ionic form like iodide)

### I2
- **I**: 0 (In elemental form, the oxidation state is 0)

### 2NaBr
- **Na**: +1 (Sodium is an alkali metal, usually +1)
- **Br**: -1 (Bromine is typically -1 in ionic compounds)

### Fe2O3
- **Fe**: +3 (Iron in this oxide is typically in the +3 state)
- **O**: -2 (Oxygen usually has an oxidation state of -2)

### 2Al
- **Al**: 0 (In elemental form, the oxidation state is 0)

### Al2O3
- **Al**: +3 (Aluminum in this oxide is typically +3)
- **O**: -2 (Oxygen usually has an oxidation state of -2)

### 2Fe
- **Fe**: 0 (In elemental form, the oxidation state is 0)

### Summary:
- NF3: N +3, F -1
- K2CO3: K +1, C +4, O -2
- HIO4: H +1, I +7, O -2
- Br2: Br 0
- 2NaI: Na +1, I -1
- I2: I 0
- 2NaBr: Na +1, Br -1
- Fe2O3: Fe +3, O -2
- 2Al: Al 0
- Al2O3: Al +3, O -2
- 2Fe: Fe 0