Calculate 3H+4 for each of the following solutions, and indicate whether the solution is acidic, basic, or neutral: (b) 3OH-4 = 8.8 * 10-9 M

Video transcript

Hello everyone. So in this video we're calculating for the concentration of our H plus ions in a solution. And we're seeing if the solution is going to be acidic. Basic or neutral. Based on this calculated value. So for reference we're gonna go ahead and consider pure water at room temperature, room temperature being at 25 degrees Celsius. So we know that the kW value in standard conditions is equal to the concentration of H plus multiplied by the concentration over her hydroxide. So that's going to equal to the value of 1.0 times 10 to the negative 14. We want to just know the single values of the concentrations. We actually assume that the concentration of my H plus is equal to the concentration of O. H minus. Which then we just divide this value by two To give us 1.0 times 10 to the -7. What we can take away from this information is that if our calculated concentration of our H plus value is greater than 1.0 times 10 to the negative seven moller this solution is going to be considered acidic. Now if this calculate H plus concentration is less than 1.0 times 10 to the negative seven moller this solution would be considered as basic. Now bringing this equation back up again. So we have K. W. Equaling the concentration of the H plus, multiplied by the concentration of hydroxide. We're solving for the concentration of H plus so divide each side by the concentration of our hydroxide. To go ahead and isolate our desired value. So the concentration of H plus is equal to K. W. Over the concentration of my O. H minus, plugging in my numerical values we have kW equaling to 1. times 10 to the negative 14. And the concentration of my hydroxide is given to us in the problem that being 7.6 times 10 to the -6 molar. So once I put these values into my calculator I would get that. The concentration of my H plus is going to be 1.3 times 10 to the negative nine moller. And again we are using our reference value of 1.0 times 10 to the negative seven. We see that the calculate concentration of H plus is actually going to be less than this reference value. And therefore we can say that our solution is basic and that the calculate H plus concentration is of 1.3 times 10 to the negative nine moller. So this right here is going to be my final answer for this problem. Thank you all so much for watching