Respuesta :
Answer:
For A: The number of arsenic atoms are [tex]3.4\times 10^{21}[/tex]
For B: The percent composition of mercury, thallium and chromium in their complexes are 61.76 %, 62.2 % and 29.51 % respectively.
Explanation:
- For A:
To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
Given mass of dimercaprol = 696 mg = 0.696 g (Conversion factor: 1 g = 1000 mg)
Molar mass of dimercaprol = 124.21 g/mol
Putting values in above equation, we get:
[tex]\text{Moles of dimercaprol}=\frac{0.696g}{124.21g/mol}=0.0056mol[/tex]
According to mole concept:
1 mole of a compound contains [tex]6.022\times 10^{23}[/tex] number of molecules.
So, 0.0056 moles of dimercaprol will contain [tex]0.0056\times 6.022\times 10^{23}=3.4\times 10^{21}[/tex] number of molecules.
As, 1 molecule of dimercaprol binds with 1 atom of Arsenic
So, [tex]3.4\times 10^{21}[/tex] number of dimercaprol molecules will bind with = [tex]1\times 3.4\times 10^{21}=3.4\times 10^{21}[/tex] number of arsenic atoms
Hence, the number of arsenic atoms are [tex]3.4\times 10^{21}[/tex]
- For B:
We know that:
Molar mass of dimercaprol = 124.21 g/mol
Molar mass of mercury = 200.59 g/mol
Molar mass of thallium = 204.38 g/mol
Molar mass of chromium = 51.99 g/mol
Also, 1 molecule of dimercaprol binds with 1 metal atom.
To calculate the percentage composition of metal in a complex, we use the equation:
[tex]\%\text{ composition of metal}=\frac{\text{Mass of metal}}{\text{Mass of complex}}\times 100[/tex] ......(1)
- For mercury:
Mass of Hg-complex = (200.59 + 124.21) = 324.8 g
Mass of mercury = 200.59 g
Putting values in equation 1, we get:
[tex]\%\text{ composition of mercury}=\frac{200.59g}{324.8g}\times 100=61.76\%[/tex]
- For thallium:
Mass of Tl-complex = (204.38 + 124.21) = 328.59 g
Mass of thallium = 204.38 g
Putting values in equation 1, we get:
[tex]\%\text{ composition of thallium}=\frac{204.38g}{328.59g}\times 100=62.2\%[/tex]
- For chromium:
Mass of Cr-complex = (51.99 + 124.21) = 176.2 g
Mass of chromium = 51.99 g
Putting values in equation 1, we get:
[tex]\%\text{ composition of chromium}=\frac{51.99g}{176.2g}\times 100=29.51\%[/tex]
Hence, the percent composition of mercury, thallium and chromium in their complexes are 61.76 %, 62.2 % and 29.51 % respectively.
