Answer:
The work done on the system is 17.75_KJ
Explanation:
To solve this question we need to know the required equations from the given variables, thus
Initial volume = 85L
Final volume = 12L
External pressure = 2.4 atm.
work done = - PΔV
2.4×(85-12) = 175.2L×atm
Converting from L•atm to KJ is given by
1 L•atm = 0.1013 kJ
(175.2 L•atm) * (0.1013 kJ / 1 L•atm)
= 17.75 kJ
The work done on the system is 17.75_KJ
Answer:
Pb: 22.4 at%
Sn: 77.6 at%
Explanation:
It is possible to find at% of Pb and Sn converting mass in moles using molar mass assuming a basis of 100g, thus:
Pb: 33.5g × (1mol / 207.2g) = <em>0.1617mol</em>
Sn: 66.5g × (1mol / 118.7g) = <em>0.5602mol</em>
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Total moles: 0.1617mol + 0.5602mol = 0.7219mol
Composition in at%:
Pb: 0.1617mol / 0.7219mol × 100 = <em>22.4 at%</em>
Sn: 0.5602mol / 0.7219mol × 100 = <em>77.6 at%</em>
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I hope it helps!
The fact that most alpha particles went straight through the foil is evidence for the atom being mostly empty space. A small number of alpha particles being deflected at large angles suggested that there is a concentration of positive charge in the atom.
Answer:
I'm pretty sure its just the mass of the sample divided by the molar mass
for example if I had like 7g of carbon and wanted to find the moles, I would divide the mass I have (7g) by the molar mass (the atomic mass value on your periodic table, in this case for carbon it would be 14g)
moles = 
Hope this helped
