We are going to use Avogadro's constant to calculate how many molecules of
carbons dioxide exist in lungs:
when 1 mole of CO2 has 6.02 x 10^23 molecules, so how many molecules in
CO2 when the number of moles is 5 x 10^-2
number of molecules = moles of CO2 * Avogadro's number
= 5 x 10^-2 * 6.02 x 10^23
= 3 x 10^22 molecules
∴ There are 3 x 10^22 molecules in CO2 exist in lungs
Answer:
![t=23.5min](https://tex.z-dn.net/?f=t%3D23.5min)
Explanation:
Hello,
In this case, since the rate equation turns out as shown below due to the first-order kinetics:
![\frac{dC_A}{dt}=-kC_A](https://tex.z-dn.net/?f=%5Cfrac%7BdC_A%7D%7Bdt%7D%3D-kC_A)
Its integration results:
![\int\limits^{C_A}_{C_A^0} { \frac{dC_A}{C_A}} \,=-k\int\limits^t_0 {} \, dt\\ln(\frac{C_A}{C_A^0})=-kt](https://tex.z-dn.net/?f=%5Cint%5Climits%5E%7BC_A%7D_%7BC_A%5E0%7D%20%7B%20%5Cfrac%7BdC_A%7D%7BC_A%7D%7D%20%5C%2C%3D-k%5Cint%5Climits%5Et_0%20%7B%7D%20%5C%2C%20dt%5C%5Cln%28%5Cfrac%7BC_A%7D%7BC_A%5E0%7D%29%3D-kt)
However, the rate constant is computed by considering the given half-life time as follows:
![k=\frac{ln(2)}{t_{1/2}}=\frac{ln(2)}{2.42x10^3s}=2.86x10^{-4}s^{-1}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7Bln%282%29%7D%7Bt_%7B1%2F2%7D%7D%3D%5Cfrac%7Bln%282%29%7D%7B2.42x10%5E3s%7D%3D2.86x10%5E%7B-4%7Ds%5E%7B-1%7D)
In such a way, the required time in minutes to diminish the concentration by 66.8% of the initial turns out:
![C_A=0.668C_A^0](https://tex.z-dn.net/?f=C_A%3D0.668C_A%5E0)
![ln(\frac{0.668C_A^0}{C_A^0})=-kt](https://tex.z-dn.net/?f=ln%28%5Cfrac%7B0.668C_A%5E0%7D%7BC_A%5E0%7D%29%3D-kt)
![t=\frac{-ln(0.668)}{2.86x10^{-4}s^1}=1408.3s*\frac{1min}{60s} \\t=23.5min](https://tex.z-dn.net/?f=t%3D%5Cfrac%7B-ln%280.668%29%7D%7B2.86x10%5E%7B-4%7Ds%5E1%7D%3D1408.3s%2A%5Cfrac%7B1min%7D%7B60s%7D%20%5C%5Ct%3D23.5min)
Best regards.
Your answer should be "D."
Early computers were like "walkie-talkies."
They were used by the government to exchange all sorts of data during the Cold War.
I hope this helps! :)
The orbital number indicates the energy lvl
The energy called Activation Energy (Ea) is required in all chemical cells during a chemical reaction. Sorry if I am wrong.