what is the mass of 3 moles of Br2?
The Correct Answer and Explanation is:
Answer:
The molar mass of Br₂ (bromine molecule) is approximately 159.8 g/mol.
To calculate the mass of 3 moles of Br₂:Mass=Number of moles×Molar mass\text{Mass} = \text{Number of moles} \times \text{Molar mass}Mass=Number of moles×Molar massMass=3 mol×159.8 g/mol=479.4 g\text{Mass} = 3 \, \text{mol} \times 159.8 \, \text{g/mol} = \boxed{479.4 \, \text{g}}Mass=3mol×159.8g/mol=479.4g
Explanation
In chemistry, the concept of the mole is central to quantifying substances involved in chemical reactions. One mole of any substance contains Avogadro’s number of particles, which is approximately 6.022×10236.022 \times 10^{23}6.022×1023 particles. For elements and compounds, the mass of one mole—known as the molar mass—is numerically equal to the relative atomic or molecular mass expressed in grams.
Bromine is a halogen that exists naturally as a diatomic molecule, Br₂. Each bromine atom has an atomic mass of approximately 79.9 atomic mass units (amu). Therefore, the molar mass of Br₂ is calculated as:79.9 g/mol×2=159.8 g/mol79.9 \, \text{g/mol} \times 2 = 159.8 \, \text{g/mol}79.9g/mol×2=159.8g/mol
This means one mole of Br₂ has a mass of 159.8 grams. To determine the mass of multiple moles of Br₂, use the relationship:Mass=moles×molar mass\text{Mass} = \text{moles} \times \text{molar mass}Mass=moles×molar mass
Given 3 moles of Br₂, multiply the number of moles by the molar mass:3×159.8=479.4 g3 \times 159.8 = 479.4 \, \text{g}3×159.8=479.4g
Thus, 3 moles of bromine molecules have a total mass of 479.4 grams.
Understanding molar mass is essential for stoichiometry, which involves calculating the quantities of reactants and products in chemical reactions. Using molar mass allows accurate conversion between mass and moles, enabling proper measurements and predictions in both laboratory and industrial chemical processes. For diatomic elements like Br₂, it is crucial to consider the molecular form rather than the atomic form to obtain correct values during calculations.
