Addition of phenolphthalein to an unknown colorless solution does not cause a color change. The addition of bromthymol blue to the same solution leads to a yellow color. (c) What other indicator or indicators would you want to use to determine the pH of the solution more precisely?

Video transcript

Hello everyone today we are being told that an unknown colorless solution turns red when para metal red is added it turns orange when Aretha racine is added, choose another indicator that will give a more precise value for the ph of the solution. So if we want to make a chart to indicate that we have our indicator, the ph change and the color change we can do so here and so we have our param Ethelred and our urine throw scene. So what does abbreviate those as such? And so according to Our lab values in our textbooks, this may be present in your textbook. We have that pair of methyl red has a ph change between one and three and that scene has a ph change between 2.2 and 3.6. And that paramedical red has a color change of red to yellow and that person has a color change of orange to red. And so we can say that the solution is a lower ph when paramedical read and seen are added. So we have lower phs when these two indicators are added And so therefore we need to find an indicator. So we need to find an indicator with a ph change Between one and 2.2. And so according to another reference value, our ph change for Our meta crystal purple here is going to be 1.2-2. For our thermal failing we have our 9.4 to our 10.6 for our quick Aldine red we have 1-2.2 for Ethelred we have our 3.82 are 6.4. And so looking at these values, we can see that we have to that fit within that range we ever met a crystal purple and we have our quenelle dean read. And with that we have our answer. I hope this helped, and until next time.