Answer:
0.387 g
Explanation:
pH of the buffer = 1
V = Volume of solution = 100 mL
[HA] = Molarity of HA = 0.1 M
= Acid dissociation constant =
(assuming base as
)
Molar mass of base = 322.2 g/mol
pKa is given by

From the Henderson-Hasselbalch equation we get
![pH=pK_a+\log\dfrac{[A^-]}{[HA]}\\\Rightarrow pH-pK_a=\log\dfrac{[A^-]}{[HA]}\\\Rightarrow 10^{pH-pK_a}=\dfrac{[A^-]}{[HA]}\\\Rightarrow [A^-]=10^{pH-pK_a}[HA]\\\Rightarrow [A^-]=10^{1-1.92}\times0.1\\\Rightarrow [A^-]=0.01202\ \text{M}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%5Cdfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D%5C%5C%5CRightarrow%20pH-pK_a%3D%5Clog%5Cdfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D%5C%5C%5CRightarrow%2010%5E%7BpH-pK_a%7D%3D%5Cdfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D%5C%5C%5CRightarrow%20%5BA%5E-%5D%3D10%5E%7BpH-pK_a%7D%5BHA%5D%5C%5C%5CRightarrow%20%5BA%5E-%5D%3D10%5E%7B1-1.92%7D%5Ctimes0.1%5C%5C%5CRightarrow%20%5BA%5E-%5D%3D0.01202%5C%20%5Ctext%7BM%7D)
Moles of base

Mass of base is given by

The required mass of the base is 0.387 g.
There are 21 atoms represented in the formula :) hope this helped.
Answer:
S₁₂
Explanation:
The freezing point depression (ΔTf) is a colligative property that can be calculated using the following expression.
ΔTf = Kf × m
where,
Kf: freezing point depression
m: molality
ΔTf = Kf × m
m = ΔTf / Kf
m = 0.156 °C / (29.8 °C/m)
m = 5.23 × 10⁻³ m
The molality is:
m = moles of solute / kilograms of solvent
moles of solute = m × kilograms of solvent
moles of solute = 5.23 × 10⁻³ mol/kg × 0.5000 kg
moles of solute = 2.62 × 10⁻³ mol
1.00 g corresponds to 2.62 × 10⁻³ moles. The molar mass of Sₙ is:
1.00 g/2.62 × 10⁻³ mol = 382 g/mol
We can calculate n.
n = molar mass of Sₙ / molar mass of S
n = (382 g/mol) / (32.0 g/mol)
n = 11.9 ≈ 12
The molar formula is S₁₂.
Answer:
2,2,3,3-tetrapropyloxirane
Explanation:
In this case, we have to know first the alkene that will react with the peroxyacid. So:
<u>What do we know about the unknown alkene? </u>
We know the product of the ozonolysis reaction (see figure 1). This reaction is an <u>oxidative rupture reaction</u>. Therefore, the double bond will be broken and we have to replace the carbons on each side of the double bond by oxygens. If
is the only product we will have a symmetric molecule in this case 4,5-dipropyloct-4-ene.
<u>What is the product with the peroxyacid?</u>
This compound in the presence of alkenes will produce <u>peroxides.</u> Therefore we have to put a peroxide group in the carbons where the double bond was placed. So, we will have as product <u>2,2,3,3-tetrapropyloxirane.</u> (see figure 2)
The law of conservation of energy is one of the most commonly used principles in physics and chemistry wherein it states that "Energy<span> can neither be created nor destroyed; rather, it transforms from one form to another." Therefore, the energy entering the system, should be equal to the amount of energy leaving the system.</span>