H2O is a compound. So it's second one.
Explanation:
solution has a pH of 2 is a strong acid.
Through manipulation of equations, we are able to obtain the equation:
![-pOH= log [ OH^{-}]](https://tex.z-dn.net/?f=-pOH%3D%20log%20%5B%20OH%5E%7B-%7D%5D%20)
Then we can transform the equation into:
![[ OH^{-}]= 10^{-pOH}](https://tex.z-dn.net/?f=%5B%20OH%5E%7B-%7D%5D%3D%2010%5E%7B-pOH%7D%20%20)
Then we are able to plug in the pOH and directly get [OH-]:
![[ OH^{-}] = 10^{-6.48}](https://tex.z-dn.net/?f=%5B%20OH%5E%7B-%7D%5D%20%3D%2010%5E%7B-6.48%7D%20)
Answer:
ELEMENTS MIXTURE
Elements are made up of one kind of atoms. Mixtures are made up of two or more kinds of Compounds .
Elements cannot be broken down into simpler substances by any physical or chemical method. The various constituents are seperated by simple physical means