For the answer to the question above, <span>The formula for freezing point depression is </span>
<span>ΔTf = mkfi </span>
<span>kf is the freezing point constant </span>
<span>i is the Van't Hoff factor which in this case is 1 </span>
<span>m is molality (moles of solute/kg of solvent) </span>
<span>ΔTf is temperature change </span>
<span>ΔTf is 2.17 °C, the molality is the amount of solute Quinine </span>
<span>in the solvent cyclohexane. We cannot calculate moles therefore we need to substitute moles with g/mm. </span>
<span>moles = g/mm so molality=(g/mm)/kg </span>
<span>molality = (0.845/mm)/0.025 = 33.8/mm </span>
<span>2.17 = 33.8/mm(20.8) rearrange </span>
<span>mm = (33.8/2.17)(20.8) = 324g/mol</span>
Answer:
0.529
Explanation:
Let's consider the reaction A → Products
Since the units of the rate constant are s⁻1, this is a first-order reaction with respect to A.
We can find the concentration of A at a certain time t (![[A]_{t}](https://tex.z-dn.net/?f=%5BA%5D_%7Bt%7D)
) using the following expression.
![[A]_{t}=[A]_{0}.e^{-k\times t}](https://tex.z-dn.net/?f=%5BA%5D_%7Bt%7D%3D%5BA%5D_%7B0%7D.e%5E%7B-k%5Ctimes%20t%7D)
where,
[A]₀: initial concentration of A
k: rate constant
![[A]_{t}=0.548M.e^{-3.6\times 10^{-4}s^{-1}\times 99.2s }](https://tex.z-dn.net/?f=%5BA%5D_%7Bt%7D%3D0.548M.e%5E%7B-3.6%5Ctimes%2010%5E%7B-4%7Ds%5E%7B-1%7D%5Ctimes%2099.2s%20%7D)
![[A]_{t}=0.529 M](https://tex.z-dn.net/?f=%5BA%5D_%7Bt%7D%3D0.529%20M)
The correct answer is <span>Antoine-Laurent de Lavoisier. Hope this helps!</span>
