Calculate the formula mass of magnesium bromate, Mg(BrO3)2, in atomic mass units (amu or u).
The Correct Answer and Explanation is :
To calculate the formula mass of magnesium bromate, Mg(BrO3)2, we need to determine the atomic masses of the elements involved and sum them according to the stoichiometric coefficients in the formula.
Step 1: List the elements and their atomic masses
- Magnesium (Mg): Atomic mass = 24.305 amu
- Bromine (Br): Atomic mass = 79.904 amu
- Oxygen (O): Atomic mass = 15.999 amu
Step 2: Break down the chemical formula
The chemical formula for magnesium bromate is Mg(BrO3)2. This means there is:
- 1 magnesium atom (Mg)
- 2 bromine atoms (Br)
- 6 oxygen atoms (O), since there are 2 (BrO3) groups, and each group contains 3 oxygen atoms.
Step 3: Calculate the total mass for each element
- Magnesium (Mg): There is 1 magnesium atom.
[
\text{Mass of Mg} = 1 \times 24.305 \, \text{amu} = 24.305 \, \text{amu}
] - Bromine (Br): There are 2 bromine atoms.
[
\text{Mass of Br} = 2 \times 79.904 \, \text{amu} = 159.808 \, \text{amu}
] - Oxygen (O): There are 6 oxygen atoms.
[
\text{Mass of O} = 6 \times 15.999 \, \text{amu} = 95.994 \, \text{amu}
]
Step 4: Add the masses together
Now, sum the individual atomic masses:
[
\text{Total mass of Mg(BrO3)2} = 24.305 \, \text{amu} + 159.808 \, \text{amu} + 95.994 \, \text{amu}
]
[
\text{Total mass of Mg(BrO3)2} = 280.107 \, \text{amu}
]
Final Answer:
The formula mass of magnesium bromate, Mg(BrO3)2, is 280.107 amu.
Explanation:
The formula mass is the sum of the atomic masses of all atoms in the compound, considering the quantity of each type of atom based on the chemical formula. Magnesium bromate contains one magnesium atom, two bromine atoms, and six oxygen atoms. By multiplying the atomic masses of each element by the number of atoms of that element in the formula and then summing these values, we arrive at the formula mass of 280.107 amu. This is the mass of one molecule of magnesium bromate.