Number of moles:
1 mole ---------- 6.02x10²³ molecules
? moles --------- 9.45x10²⁴ molecules
1 x ( 9.45x10²⁴) / 6.02x10²³ =
9.45x10²⁴ / 6.02x10²³ => 15.69 moles of CH3OH
Therefore:
Molar mass CH3OH = 32.04 g/mol
1 mole ------------ 32.04 g
15.69 moles ----- mass methanol
Mass methanol = 15.69 x 32.04 / 1 => 502.7076 g
The mass of Ba(IO3)2 that can be dissolved in 500 ml of water at 25 degrees celcius is 2.82 g
<h3>What mass of Ba(IO3)2 can be dissolved in 500 ml of water at 25 degrees celcius?</h3>
The Ksp of Ba(IO3)2 = 1.57 × 10^-9
Molar mass of Ba(IO3)2 = 487 g/mol?
Dissociation of Ba(IO3)2 produces 3 moles of ions as follows:

![Ksp = [Ba^{2+}]*[IO_{3}^{-}]^{2}](https://tex.z-dn.net/?f=Ksp%20%3D%20%5BBa%5E%7B2%2B%7D%5D%2A%5BIO_%7B3%7D%5E%7B-%7D%5D%5E%7B2%7D)
![[Ba(IO_{3})_{2}] = \sqrt[3]{ksp} =\sqrt[3]{1.57 \times {10}^{ - 9} } \\ [Ba(IO_{3})_{2}] = 1.16 \times {10}^{-3} moldm^{-3}](https://tex.z-dn.net/?f=%5BBa%28IO_%7B3%7D%29_%7B2%7D%5D%20%3D%20%20%5Csqrt%5B3%5D%7Bksp%7D%20%3D%3C%2Fp%3E%3Cp%3E%5Csqrt%5B3%5D%7B1.57%20%5Ctimes%20%20%7B10%7D%5E%7B%20-%209%7D%20%7D%20%5C%5C%20%20%5BBa%28IO_%7B3%7D%29_%7B2%7D%5D%20%3D%201.16%20%5Ctimes%20%20%7B10%7D%5E%7B-3%7D%20moldm%5E%7B-3%7D)
moles of Ba(IO3)2 = 1.16 × 10^-3 × 0.5 = 0.58 × 10^-3 moles
mass of Ba(IO3)2 = 0.58 × 10^-3 moles × 487 = 2.82 g
Therefore, mass Ba(IO3)2 that can be dissolved in 500 ml of water at 25 degrees celcius is 2.82 g.
Learn more about mass and moles at: brainly.com/question/15374113
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<u>Answer:</u> The spacing between the crystal planes is 
<u>Explanation:</u>
To calculate the spacing between the crystal planes, we use the equation given by Bragg, which is:

where,
n = order of diffraction = 2
= wavelength of the light =
(Conversion factor:
)
d = spacing between the crystal planes = ?
= angle of diffraction = 22.20°
Putting values in above equation, we get:

Hence, the spacing between the crystal planes is 