Question

give the following chemical formula,molar mass,&% composition of the following problems.Round to the nearest tenths place
1)Tetrabromine octaflouride

Answer 1

To find the chemical formula, molar mass, and percent composition of tetrabromine octafluoride, we first need to determine its chemical formula, which is \( \text{Br}_4\text{F}_8 \).

### 1. Molar Mass Calculation:

- Molar mass of Bromine (Br): \( 79.904 \, \text{g/mol} \)
- Molar mass of Fluorine (F): \( 18.998 \, \text{g/mol} \)

Now we calculate the molar mass of \( \text{Br}_4\text{F}_8 \):

\[
\text{Molar mass} = (4 \times 79.904) + (8 \times 18.998)
\]

Calculating each part:

- For Bromine: \( 4 \times 79.904 = 319.616 \, \text{g/mol} \)
- For Fluorine: \( 8 \times 18.998 = 151.984 \, \text{g/mol} \)

Now, adding these together:

\[
\text{Total molar mass} = 319.616 + 151.984 = 471.600 \, \text{g/mol}
\]

### 2. Percent Composition Calculation:

Now we will find the percent composition of each element in \( \text{Br}_4\text{F}_8 \):

- **Percent of Bromine**:
\[
\text{Percent of Br} = \left( \frac{319.616}{471.600} \right) \times 100 \approx 67.8\%
\]

- **Percent of Fluorine**:
\[
\text{Percent of F} = \left( \frac{151.984}{471.600} \right) \times 100 \approx 32.2\%
\]

### Summary:
- **Chemical Formula:** \( \text{Br}_4\text{F}_8 \)
- **Molar Mass:** \( 471.6 \, \text{g/mol} \)
- **Percent Composition:**
- Br: \( 67.8\% \)
- F: \( 32.2\% \)