Answer:
The correct answer is 399.8 ppm
Explanation:
A concentration in parts per million (ppm) is equal to:
![1 ppm = \frac{1 g solute}{10^{6}g solution}= \frac{1 mg solute}{1 kg solution}](https://tex.z-dn.net/?f=1%20ppm%20%3D%20%5Cfrac%7B1%20g%20solute%7D%7B10%5E%7B6%7Dg%20solution%7D%3D%20%5Cfrac%7B1%20mg%20solute%7D%7B1%20kg%20solution%7D)
Solute: Cd; Mass = 180 mg x (1 g/1000 mg) = 0.18 g
Solvent: Water ; Mass= 450.0 g x (1 kg/1000 g) = 0.45 kg
We have the following total mass of solution:
Mass of solution = Mass of solute + Mass of solvent = 0.18 g + 450 g = 450.18 g = 0.45018 kg
Finally, we divide the <u>mass of solute (in mg)</u> into the <u>mass of solution (in kg)</u> to obtain the ppm (in mg/Kg):
ppm = 180 mg/0.45018 kg = 399.8 mg/Kg = 399.8 ppm
Oceans, they are larger than ponds hence they possess wider exposure with more number of surface molecules.
Answer : The concentration of AB after 14.0 s is, 0.29 M
Explanation :
The expression used for second order kinetics is:
![kt=\frac{1}{[A_t]}-\frac{1}{[A_o]}](https://tex.z-dn.net/?f=kt%3D%5Cfrac%7B1%7D%7B%5BA_t%5D%7D-%5Cfrac%7B1%7D%7B%5BA_o%5D%7D)
where,
k = rate constant = ![0.20M^{-1}s^{-1}](https://tex.z-dn.net/?f=0.20M%5E%7B-1%7Ds%5E%7B-1%7D)
t = time = 14.0 s
= final concentration = ?
= initial concentration = 1.50 M
Now put all the given values in the above expression, we get:
![0.20\times 14.0=\frac{1}{[A_t]}-\frac{1}{1.50}](https://tex.z-dn.net/?f=0.20%5Ctimes%2014.0%3D%5Cfrac%7B1%7D%7B%5BA_t%5D%7D-%5Cfrac%7B1%7D%7B1.50%7D)
![[A_t]=0.29M](https://tex.z-dn.net/?f=%5BA_t%5D%3D0.29M)
Therefore, the concentration of AB after 14.0 s is, 0.29 M
The answer is C) A length of one day