How many total sodium ions are present in one formula uint of sodium ethane-1,2-diaminetetraacetatochromate (II) and sodium hexanitrito cobaltate (III) ?

Answer

To determine the total number of sodium ions present in one formula unit of sodium ethane-1,2-diaminetetraacetatochromate(II) and sodium hexanitrito cobaltate(III), we will analyze each compound separately.

### Step 1: Analyze Sodium Ethane-1,2-diaminetetraacetatochromate(II)

1. **Identify the components**:
- The compound is sodium ethane-1,2-diaminetetraacetatochromate(II).
- Here, sodium (Na) is the cation, and the rest forms the anionic part.

2. **Determine the oxidation state of chromium**:
- The oxidation state of chromium in this compound is +2.

3. **Identify the charge of the ligand**:
- Ethane-1,2-diaminetetraacetate (EDTA) has a charge of -4.

4. **Calculate the total charge of the anionic part**:
- The total charge from the coordination sphere is:
\[ \text{Charge from chromium} (+2) + \text{Charge from EDTA} (-4) = -2 \]

5. **Determine the number of sodium ions**:
- Since the anionic part has a charge of -2, the cationic part (sodium ions) must balance this with a total charge of +2.
- Therefore, we need 2 sodium ions:
\[ \text{Total sodium ions from this compound} = 2 \]

### Step 2: Analyze Sodium Hexanitrito Cobaltate(III)

1. **Identify the components**:
- The compound is sodium hexanitrito cobaltate(III).
- Again, sodium (Na) is the cation, and the rest forms the anionic part.

2. **Determine the oxidation state of cobalt**:
- The oxidation state of cobalt in this compound is +3.

3. **Identify the charge of the ligand**:
- Hexanitrito means there are 6 nitrito (NO2) ligands, each contributing a charge of -1.
- Therefore, the total charge from the nitrito ligands is:
\[ 6 \times (-1) = -6 \]

4. **Calculate the total charge of the anionic part**:
- The total charge from the coordination sphere is:
\[ \text{Charge from cobalt} (+3) + \text{Charge from nitrito} (-6) = -3 \]

5. **Determine the number of sodium ions**:
- Since the anionic part has a charge of -3, the cationic part (sodium ions) must balance this with a total charge of +3.
- Therefore, we need 3 sodium ions:
\[ \text{Total sodium ions from this compound} = 3 \]

### Step 3: Calculate the total number of sodium ions

- Now, we can sum the sodium ions from both compounds:
\[ \text{Total sodium ions} = 2 + 3 = 5 \]

### Final Answer
The total number of sodium ions present in one formula unit of sodium ethane-1,2-diaminetetraacetatochromate(II) and sodium hexanitrito cobaltate(III) is **5**.

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