Answer: 0.082 atm L k^-1 mole^-1
Explanation:
Given that:
Volume of gas (V) = 62.0 L
Temperature of gas (T) = 100°C
Convert 100°C to Kelvin by adding 273
(100°C + 273 = 373K)
Pressure of gas (P) = 250 kPa
[Convert pressure in kilopascal to atmospheres
101.325 kPa = 1 atm
250 kPa = 250/101.325 = 2.467 atm]
Number of moles (n) = 5.00 moles
Gas constant (R) = ?
To get the gas constant, apply the formula for ideal gas equation
pV = nRT
2.467 atm x 62.0L = 5.00 moles x R x 373K
152.954 atm•L = 1865 K•mole x R
To get the value of R, divide both sides by 1865 K•mole
152.954 atm•L / 1865 K•mole = 1865 K•mole•R / 1865 K•mole
0.082 atm•L•K^-1•mole^-1 = R
Thus, the value of gas constant is 0.082 atm L k^-1 mole^-1
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!
