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
.
No, because there’s 6 Oxygens going in and only 3 going out. To balance:
2S+3O2 -> 2SO3
Your answer would be 58.12g/mol ;)
卂几丂山乇尺
As the name indicate that in 1-octene there is a double bond on the first position in the eight carbon atoms chain THUS to detect its presence, we use bromine water test;
Add bromine water to the test tube containing octane/octene if the brown colour of bromine water disappears then octene is present.
