Question

-Using vegtable indicators to dtermine Ph

what effect would the initial color of a tested solution have your determanation of the ph? For example, what effect would the purple color of grape juice have on your determination ?

we tested vitaminc C, lemon juice, diet and normal cocacola, 7 up, hand soap, sucrose, mouth wash, ammonia, as the solutes with purple grape juice as the solvent in different test tubes to determine Ph by looking at the color.

Answer 1

The procedure is not mentioned; hence, I will hazard a guess. I believe you are trying to determine the pH of a solution by identifying the color change and matching the color change with a pH strip indicator. A purple colored grape juice will have an intense color. The pH change of a solution is usually a sharp change in color from say light blue to pink or colorless to light orange. The intense color of the grape juice will mask the sharp color change and the detection of the pH change will be difficult, most likely impossible unless the grape juice is significantly diluted to have a very pale color. Moreover, some of the tested solutes like cola will have a very dark color itself and the subtle change of color due to pH change will be difficult to identify.