Answer:
The lungs and respiratory system allow oxygen in the air to be taken into the body, while also letting the body get rid of carbon dioxide in the air breathed out. When you breathe in, the diaphragm moves downward toward the abdomen, and the rib muscles pull the ribs upward and outward.
Explanation:
Answer : The concentration of
ion is, 
Solution : Given,
pH = 4.20
First we have to calculate the pOH.
As we know that,




Now we have to calculate the concentration of
ion.
![pOH=-\log [OH^-]](https://tex.z-dn.net/?f=pOH%3D-%5Clog%20%5BOH%5E-%5D)
![9.8=-\log [OH^-]](https://tex.z-dn.net/?f=9.8%3D-%5Clog%20%5BOH%5E-%5D)
![[OH^-]=1.58\times 10^{-10}M](https://tex.z-dn.net/?f=%5BOH%5E-%5D%3D1.58%5Ctimes%2010%5E%7B-10%7DM)
Therefore, the concentration of
ion is, 
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