Calculate 3OH-4 for each of the following solutions, and indicate whether the solution is acidic, basic, or neutral: (a) 3H+4 = 0.0505 M

Video transcript

Hello everyone. So in this video we're calculating for the concentration of our hydroxide and seeing if the solution is going to be acidic, basic or neutral based on this value. So as a reference point, we're gonna go ahead and consider pure water at room temperature, room temperature being at 25 degrees Celsius. So we know that in the standard conditions that the K. W. Is equal to the concentration of H plus kerryon multiplied by our hydroxide and ion And that equals to 1.0 times to the -14. So manipulating this equation, we know that the H plus is equal to the concentration of R. O. H. Which is equal to 1.0 times 10 to the negative seven. So I'm just dividing this value by two. What we can get out of these numbers is that the concentration of O. H. If that is going to be greater than 1.0 times 10 to the negative seven moller this solution is going to be considered basic. If the concentration of hydroxide is going to be less than the 1.0 times 10 to the -7 moller this will be considered acidic. So bringing back this equation that we just wrote here, we know that KW equals to the concentration of H plus, multiplied by the concentration of O H minus. We want to go ahead and isolate for the concentration of hydroxide. So we'll just divide both sides by the concentration of H. Plus that would give us K. W on top and H plus on the bottom plug in those numerical values. My kw is again 1.0 times 10 to the negative 14. And my concentration of H plus is 1.0 times 10 to the negative seven. I apologize we are given this value. So in the problem the states that is 3.4 times 10 to the -9 moller. Putting that value into my calculator, I would get that. The concentration of my hydroxide is equal to 2. times 10 to the negative six Moeller. Again, we're going to compare this to the reference value of 1.0 times 10 to the negative seven molar. I can see that the concentration of my O. H. Is actually going to be greater than my reference value and therefore we can conclude that this solution is going to be basic. So we have a basic solution and that the concentration of my H is going to be 2.9 times 10 to the negative six moller. And this right here is going to be my final answer for this problem. Thank you all so much for watching