The mass of piece of sterling silver jewelry is 33.24 g. It contains 92.5% silver Ag by mass. Since, sterling silver is an alloy of Ag-Cu thus, percentage of Cu will be:
% Cu=100-92.5=7.5%
Thus, mass of copper will be:
Molar mass of Cu is 63.546 g/mol, thus, number of moles of Cu can be calculated as follows:
Here, m is mass and M is molar mass.
Putting the values,
Now, in 1 mole of Cu there are thus, in 0.03923 mol, number of Cu atoms will be:
Thus, number of atoms of Cu will be.
Answer:
1) Favor formation of reactant
2) Favor formation of product
3) Favor formation of product
4) Favor formation of product
5) Favor formation of product
Explanation:
The reaction is
The reaction is endothermic
1. Adding hydrobromic acid (HBr)
It will increase the amount of bromide ion. Bromide ion is one of the product so it will favor formation of reactant.
2. Lowering the concentration of bromide (Br-) ions
As we are decreasing the the concentration of product it will favor formation of more products
3. Heating the concentrations
If we are heating the mixture, it will increase the temperature and it will favor endothermic reaction. Thus will favor formation of product.
4. Adding solid silver bromide (AgBr)
If we are adding silver bromide it means we are increasing the concentration of reactant, it will favor formation of products
5. Removing silver (Ag+) ions
Removing silver ions means we are decreasing the concentration of product thus it will favor formation of products.