How do you find the molar mass of HBr?
The correct answer and explanation is:
To find the molar mass of hydrogen bromide (HBr), you need to sum the atomic masses of hydrogen (H) and bromine (Br). The molar mass of a compound is the sum of the atomic masses of all its atoms.
- Find the atomic mass of hydrogen:
The atomic mass of hydrogen (H) is approximately 1.008 g/mol. - Find the atomic mass of bromine:
The atomic mass of bromine (Br) is approximately 79.904 g/mol. - Add the atomic masses:
The molar mass of HBr is calculated by adding the atomic mass of hydrogen and the atomic mass of bromine: Molar mass of HBr=1.008 g/mol+79.904 g/mol=80.912 g/mol\text{Molar mass of HBr} = 1.008 \, \text{g/mol} + 79.904 \, \text{g/mol} = 80.912 \, \text{g/mol}
So, the molar mass of HBr is approximately 80.912 g/mol.
Explanation:
The molar mass is a fundamental property of substances and is essential when performing calculations in chemistry, such as determining the number of moles in a given mass of a substance. The atomic masses listed on the periodic table represent the average mass of atoms of an element, taking into account the isotopes of the element and their relative abundances. In the case of HBr, the element hydrogen has a single isotope with an atomic mass of about 1.008 g/mol, while bromine has two naturally occurring isotopes. The value used for bromine’s atomic mass reflects the weighted average of these isotopes.
This approach applies to any molecular compound. For example, if you were calculating the molar mass of a more complex molecule, you would simply add the atomic masses of each element in the compound, taking into account how many atoms of each element are present in the formula. This information is crucial when determining how much of a substance is needed to react with another substance in a chemical reaction, especially when using stoichiometry to solve problems.