When creating mixture the amount of hydrogen gas is directly related to the concentration of the acid mixture, the higher the concentration level The more hydrogen gas would be produced.
Among the given choices NH₃/NH₄Cl is the best choice to prepare pH = 9.0 because pKa of the salt of NH₄<span>Cl nearly equals to 9 (pKb = 4.75, hence pKa = 14 - pKb = 14 - 4.75 = 9.25). A buffer can't change its pH +/- pKa, so this combination is best to prepare desired pH.</span>
Answer:
it going to be a Chemical change
Explanation:
it had a reaction with oxygen and and that formed iron oxide
Answer:
I guess number three (3) Is wrong