7.72 g of CuBr2 contains how many bromide (Br-) ions?
7.72g/molar mass CuBr2 = moles CuBr2.
There are 6.922E23 molecules in 1 mole.
There are two Br ions per molecule.
To determine the number of bromide (Br-) ions in 7.72 g of CuBr2, we need to consider the formula of CuBr2 and understand its structure.
The formula of CuBr2 indicates that one copper (Cu) atom is combined with two bromine (Br) atoms. This implies that each molecule of CuBr2 contains two bromide ions.
To calculate the number of bromide ions, we first need to determine the number of moles of CuBr2. We can use the formula:
moles = mass / molar mass
The molar mass of CuBr2 can be calculated by adding the atomic masses of copper (Cu) and two bromine (Br) atoms.
The atomic mass of copper (Cu) is approximately 63.55 g/mol, and the atomic mass of bromine (Br) is approximately 79.90 g/mol.
So, the molar mass of CuBr2 is:
(63.55 g/mol) + 2 * (79.90 g/mol) = 223.35 g/mol
Now, we can calculate the number of moles of CuBr2:
moles = 7.72 g / 223.35 g/mol = 0.0345 mol
Since each molecule of CuBr2 contains 2 bromide ions, we can multiply the number of moles by 2 to determine the number of bromide ions:
0.0345 mol * 2 = 0.0690 mol
Therefore, 7.72 g of CuBr2 contains approximately 0.0690 moles of bromide ions.