Fireman asked in Science & MathematicsChemistry · 1 decade ago

a compound x turns blue litmous red.It remain colourless in phenolphthalin but shows pink colour in methyl ?

orange.x is an acid or base&why?

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  • 1 decade ago
    Favourite answer

    Litmus changes color right about ph 7. Litmus is read in an acid, and blue in a base.

    Phenolphthalein changes from colorless to pink at about a pH of 8.5. Phenolphthalein is colorless below pH 8.5 and pink above pH 8.5

    Methyl orange changes color at a pH of 3.5. Below 3.5 it is red,and above 3.5 it is orange.

    If litmus changed to red and phenolphthalein remained colorless, then the solution is acidic, and it makes no difference what the methyl orange does. But since in methyl orange it is reddish, then the pH of the acid must be below 3.5.

    ===== Follow up ======

    Lest you actually believe Miss R, let me set the record straigh. Phenolphthalein does NOT change color at pH 7. At pH 7 it is colorless and at pH 8 it is colorless. It begins to change color about about pH 8.5 to 9.

    She also makes the statement, "...in a water (nuetral) which turned the solution pink. "

    Of course it is impossible for phenolphthalein to turn pink if the water was indeed neutral (pH 7). If she placed phenolphthalein in water and it turned pink, then the pH of the water was 8.5 or above. I've seen this happen, but it was because the water was made slightly basic at the water treatment plant.

  • 4 years ago

    When you have Pink and Sky blue together, a light lavender goes well. If the pink color you're using is a deep hue of pink, yellow works alright, but you may have difficulty staying true to the color scheme you're trying to achieve. If your picture is warm, yellow or variations of yellow are good. If your picture/painting is more on the cool end of things, the lavender is the way to go. Another thought, is that if the colors you are using are more pastel in nature, believe it or not a pastel orange works as well.

  • 1 decade ago

    Phenolphthalein is an indicator that turns pink in a neutral or alkalinic solution (pH equal to or greater than 7) and becomes clear when a solution becomes acidic...therefore x would have to have a pH below 7...therefore acidic...

    Source(s): Took inorganic and organic chemistry...I've used phenolphtalein in both chem classes and in physiology...we placed phenolphtalein in a water (nuetral) which turned the solution pink. We then exhaled (C02) into the solution until it turned clear which meant the pH was below 7 (acidic) because C02 is an acid when mixed with the water (carbonic acid)
  • 1 decade ago

    it is acid b'cz it has this property.............

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