How many grams are there in 4.89 moles of Calcium Bromide (CaBr2)? The molar mass of Ca is 40.08 g/mol, while Br has a molar mass of 79.90 g/mol.
The Correct Answer and Explanation is:
To calculate the mass of 4.89 moles of calcium bromide (CaBr2), we need to use the molar mass of CaBr2, which is the sum of the molar masses of calcium (Ca) and bromine (Br).
Step 1: Calculate the molar mass of CaBr2
- Molar mass of calcium (Ca) = 40.08 g/mol
- Molar mass of bromine (Br) = 79.90 g/mol
Since there are two bromine atoms in CaBr2, we multiply the molar mass of bromine by 2:
- Molar mass of CaBr2 = 40.08 g/mol + 2 × 79.90 g/mol
- Molar mass of CaBr2 = 40.08 g/mol + 159.80 g/mol
- Molar mass of CaBr2 = 199.88 g/mol
Step 2: Use the molar mass to calculate the mass of 4.89 moles
Now that we know the molar mass of CaBr2 is 199.88 g/mol, we can calculate the mass of 4.89 moles of CaBr2 using the formula:mass=moles×molar mass\text{mass} = \text{moles} \times \text{molar mass}mass=moles×molar massmass=4.89 moles×199.88 g/mol\text{mass} = 4.89 \, \text{moles} \times 199.88 \, \text{g/mol}mass=4.89moles×199.88g/molmass=977.72 grams\text{mass} = 977.72 \, \text{grams}mass=977.72grams
Conclusion
The mass of 4.89 moles of calcium bromide (CaBr2) is 977.72 grams. This is the total mass of the compound for the given number of moles, based on the molar masses of calcium and bromine.
