Answer:
Pressure = 1.14 atm
Explanation:
Hello,
This question requires us to calculate the final pressure of the bottle after thermal equilibrium.
This is a direct application of pressure law which states that in a fixed mass of gas, the pressure of a given gas is directly proportional to its temperature, provided that volume remains constant.
Mathematically, what this implies is
P = kT k = P / T
P1 / T1 = P2 / T2 = P3 / T3 =........= Pn / Tn
P1 / T1 = P2 / T2
P1 = 1.0atm
T1 = -15°C = (-15 + 273.15)K = 258.15K
P2 = ?
T2 = 21.5°C = (21.5 + 273.15)K = 294.65K
P1 / T1 = P2 / T2
P2 = (P1 × T2) / T1
P2 = (1.0 × 294.65) / 258.15
P2 = 1.14atm
The pressure of the gas after attaining equilibrium is 1.14atm
Answer: 0.4 moles
Explanation:
Given that:
Volume of gas V = 11L
(since 1 liter = 1dm3
11L = 11dm3)
Temperature T = 25°C
Convert Celsius to Kelvin
(25°C + 273 = 298K)
Pressure P = 0.868 atm
Number of moles N = ?
Note that Molar gas constant R is a constant with a value of 0.00821 atm dm3 K-1 mol-1
Then, apply ideal gas equation
pV = nRT
0.868atm x 11dm3 = n x (0.00821 atm dm3 K-1 mol-1 x 298K)
9.548 atm dm3 = n x 24.47atm dm3mol-1
n = (9.548 atm dm3 / 24.47atm dm3 mol-1)
n = 0.4 moles
Thus, there are 0.4 moles of the gas.
Mass of X₂O₇ = 54,9g
2x + 33,6g = 54,9g
2x = 54,9g - 33,6g
2x = 21,3g | :2
x = 10,65g/mol
Yes, I agree.
Chemistry can be difficult.