To find the molar mass of the compound \( AB_2 \) from the given reaction \( A + 2B \rightarrow AB_2 \), we need to calculate the molar mass using the molar masses of \( A \) and \( B \).
- Molar mass of \( A \): 8 g/mol
- Molar mass of \( B \): 12 g/mol
In the molecular formula \( AB_2 \):
- There is 1 mole of \( A \)
- There are 2 moles of \( B \)
Now we calculate the total molar mass of \( AB_2 \):
\[ \text{Molar mass of } AB_2 = (\text{molar mass of } A) + 2 \times (\text{molar mass of } B) \]
\[ \text{Molar mass of } AB_2 = 8 , \text{g/mol} + 2 \times 12 , \text{g/mol} \]
\[ \text{Molar mass of } AB_2 = 8 , \text{g/mol} + 24 , \text{g/mol} = 32 , \text{g/mol} \]
So, the correct molar mass of \( AB_2 \) is 32 g/mol.