Answer:
<u>Optical purity = 76.9231 %</u>
<u>Specific rotation of mixture = - 97.6923 °</u>
Explanation:
The mass of the racemic mixture = 3 g
It means it contains R enantiomer = 1.5 g
S enantiomer = 1.5 g
Amount of Pure R = 10 g
Total R = 11.5 g
Total volume = 500 mL + 500 mL = 1000 mL = 1 L
[R] = 11.5 g/L
[S] = 1.5 g/L
Enantiomeric excess =
=
= 76.9231 %
<u>Optical purity = 76.9231 %</u>
Also,
Optical purity = 
Optical rotation of pure enantiomer = −127 °

<u>Specific rotation of mixture = - 97.6923 °</u>
Hey there!
* Converts 1750 dm³ in liters :
1 dm³ = 1 L so 1750 dm³ = 1750 liters
* Convertes 125,000 Pa in atm :
1 Pa = 9.86*10⁻⁶ atm so 9.86*10⁻⁶ / 125,000 => 1.233 atm
* Convertes 127ºC in K :
127 + 273.15 => 400.15 K
R = 0.082 atm.L/mol.K
Finally, it uses an equation of clapeyron :
p * V = n * R * T
1.233 * 1750 = n * 0.082 * 400.15
2157.75 = n * 32.8123
n = 2157.75 / 32.8123
n = 65.76 moles
hope this helps!
<em>Calculate the pH of the following substances formed during a volcanic eruption:
</em>
<em>• Acid rain if the [H +] is 1.9 x 10-5
</em>
<em>• Sulfurous acid if [H +] = 0.10
</em>
<em>• Nitric acid if [H +] = 0.11</em>
<em />
<h3>Further explanation </h3>
pH is the degree of acidity of a solution that depends on the concentration of H⁺ ions. The greater the value the more acidic the solution and the smaller the pH.
pH = - log [H⁺]
![\tt pH=-log[1.9\times 10^{-5}]\\\\pH=5-log1.9\\\\pH=4.72](https://tex.z-dn.net/?f=%5Ctt%20pH%3D-log%5B1.9%5Ctimes%2010%5E%7B-5%7D%5D%5C%5C%5C%5CpH%3D5-log1.9%5C%5C%5C%5CpH%3D4.72)
![\tt pH=-log[10^{-1}]\\\\pH=1](https://tex.z-dn.net/?f=%5Ctt%20pH%3D-log%5B10%5E%7B-1%7D%5D%5C%5C%5C%5CpH%3D1)
![\tt pH=-log[11\times 10^{-2}]\\\\pH=2-log~11=0.959](https://tex.z-dn.net/?f=%5Ctt%20pH%3D-log%5B11%5Ctimes%2010%5E%7B-2%7D%5D%5C%5C%5C%5CpH%3D2-log~11%3D0.959)
Answer:
Activation energy is needed so reactants can move together, overcome forces of repulsion, and to begin breaking bonds.
Explanation: