Repeated patterns in the elements.
Hopefully this helps
Answer:
Explanation:
Volume of cylinder = πr²h where r is radius of cylinder, h is height of cylinder
r = d/2 = 21/2 = 10.5 cm; h = 25.2 cm
volume of cylinder = (22 * 10.5 cm * 10.5 cm * 25.2 cm) / 7
volume = 8731.8 cm³ = 8.7318 L
Using the ideal gas equation, PV = nRT
P = 4.00 MPa = 4.0 * 10³ kPa, V = 8.7318 L, R = 8.314 L.kPa/mol.K,
n = mass / molar mass
where mass = 0.474 kg or 474 g, molar mass of BF₃= 68 g/mol
n = 474 g / 68 g/mol = 6.9706 moles
making T subject of formula in the ideal gas equation;
T = PV/nR
T = (4.0 * 10³ kPa * 8.7318 L)/(6.9706 mol * 8.314 L.kPa/mol.K)
T = 602.675 K
T in °C = K - 273.15
T = 602.675 -273.15 = 329.5 °C
T = 330 °C
1) You neeed to know and use the Ksp for BaF2.
At 25°C this Ksp is 1.0 * 10 ^ - 6
2) The solutibility of BaF2 is given by:
BaF2 ⇄ Ba(2+) + 2F(-)
x 2x
=> Ksp = x * (2x)^2 = 4x^3
3) When you have a NaF solution, you have to take into accout the concentration of the NaF solution
M = 0.1
Now the equilibrium species are:
BaF2 ⇄ Ba(2+) + 2F(-)
x 2x + 0.10
And Ksp = x* [2x + 0.10]^2 = 1.0 * 10 ^ -6
Given that the Ksp << 1 you may assume that 2x << 0.1 => 2x + 0.1 ≈ 0.1
=> 1.0 * 10 ^ - 6 ≈ x(0.1)^2 = 0.01x
=> x = 1.0 * 10^ -6 / 0.01 = 1.0 * 10^ - 4 M = 0.0001 M
That is the molar solubility.
4) Now, you calculate the number of moles from the molarity's formula:
M = n / v => n = M * v = 0.0001 M * 0.500 l = 0.00005 mol
And now convert to grams,
mass in grams = number of moles * molar mass
molar mass of BaF2 = 175.34 g/mol
mass in grams = 0.00005 moles * 175.34 g / mol = 0.0088 g
Answer: 0.0088 g
Its A Hope this helps, totally didnt copy anyone.