Hey, guys, In this new video, we're gonna put to practice some of the concepts we learned about P. H and P O H. So let's take a look at the first example here it says, What is the hydroxide ion? So what's the O. H minus and the hydrogen ion concentration or hide rhodium ion concentration. Actually, that's H plus often acquis solution that has a pH equal to 6.12. So we have pH we need to find O h minus and h plus. Remember, we're able to derive a formula that connects us between H plus and pH. Remember that H plus equals 10 to the negative pH. So I would have to do now is just take that number and plug it in. When we do that, we get 7.59 times 10 to the negative seven. Now, we could find ohh now, and we confined Ohh in two different ways. Now, the first way we could find o. H minus is by simply using this equation. Kw equals H plus times. Ohh! Minus we know what K W is. We assume the temperature is 25 degrees Celsius. Since they don't tell us what it is. So this will be 1.0 times 10 to the negative 14. We just found out. What h plus is it? 7.59 times 10 to the negative seven. Now we have to find O H minus. Ohh! Mind this is our only missing variable. So just isolated. So here, o H minus would equal 1.32 times 10 to the negative eight. So that would be one way we confined O h minus. Now, the second way we could find it is if we know p o. H. We could make a connection between p o H and O H minus. So, first we'd say that pH plus p o H equals 14. We know Ph is 6.12. So let's just isolate r p o h subtract 6 12 from both sides. So p o. H equals 7.88 Remember, what's the connection between P. O. H and O H minus? You could just simply say that oh h minus equals 10 to the negative P o. H. And if you did 10 to the negative 7.88 you get the same exact answer for O. H minus. So two different methods to find the same exact missing variable. So it's basically your choice on deciding which way you want to go. Personally, I like to just find P o H and just do 10 to the negative p o. H. Because remember, if you don't put these two in brackets, your calculator may give you the incorrect answer. So it's probably always safer just to say oh h minus equals 10 to the negative P O. H.