A 2.000g sample of silver alloy was dissolved in nitric acid and then precipitated as AgBr. After drying, the sample of silver bromide weighed 2.000g. Calculate the percentage of silver in the alloy.
moles AgBr = grams/molar mass.
moles Ag = same since there is 1 Ag in 1 AgBr.
grams Ag = moles Ag x molar mass Ag
%Ag = (mass Ag/mass sample)*100 = ??
57.42%
To calculate the percentage of silver in the alloy, we need to first determine the amount of silver in the silver bromide sample.
1. Calculate the molar mass of AgBr:
The molar mass of Ag is 107.87 g/mol, and the molar mass of Br is 79.90 g/mol.
Therefore, the molar mass of AgBr is: 107.87 + 79.90 = 187.77 g/mol.
2. Calculate the number of moles of AgBr:
Since the mass of the silver bromide sample is 2.000g, we can divide it by the molar mass of AgBr to find the number of moles of AgBr:
Moles of AgBr = Mass of AgBr / Molar mass of AgBr
= 2.000g / 187.77 g/mol
3. Convert the moles of AgBr to moles of Ag:
Since each mole of AgBr contains one mole of Ag, the number of moles of Ag will be the same as the number of moles of AgBr.
4. Calculate the mass of Ag:
We can determine the mass of Ag by multiplying the number of moles of Ag by its molar mass:
Mass of Ag = Moles of Ag x Molar mass of Ag
= Moles of AgBr x Molar mass of Ag
5. Calculate the percentage of silver in the alloy:
The percentage of silver can be calculated by dividing the mass of Ag by the initial mass of the alloy and multiplying by 100:
Percentage of silver in the alloy = (Mass of Ag / Initial mass of the alloy) x 100
Now let's calculate the percentage of silver in the alloy using the given data.