Red litmus solution turns blue in basic medium i. Change in colour is due to acid or base present in sample solution. Acidic substance turning blue litmus solution into red Basic substance turning red litmus solution into blue Vinegar Lemon Juice Tamarind imli Sour milk or curd Proteins Tomatoes Apples Oranges Juice of unripe mangoes Baking soda solution Washing soda solution Bitter gourd karela extract Cucumber kheera extract.
Acidic substances turning methyl orange into pink and phenolphthalein remaining colourless Basic substances turning methyl orange into yellow and phenolphthalein into pink Vinegar Lemon Juice Tamarind imli Sour milk or curd Proteins Tomatoes Oranges Juice of unripe mangoes Baking soda solution Washing soda solution Bitter gourd karela extract Cucumber kheera extract.
Acidic substance turning blue litmus solution into red. Basic substance turning red litmus solution into blue. Baking soda solution Washing soda solution Bitter gourd karela extract Cucumber kheera extract. Basic substances turning methyl orange into yellow and phenolphthalein into pink.
Red litmus solution. Blue litmus solution. Blue litmus solution Red litmus solution Phenolphthalein Methyl orange. Red No colour change Colourless Pink. No colour change Blue Pink Yellow. The table shows the colour of methyl orange and phenolphthalein in solutions of different pH :. Indicators When an acid is dissolved in water we get an acidic solution. Litmus Litmus indicator solution turns red in acidic solutions, blue in alkaline solutions, and purple in neutral solutions.
Acids turn blue litmus paper red. The solution changes colors when it is complete. The main use of litmus is to test whether a solution is acidic or basic. Light Blue litmus paper turns red under acidic conditions and red litmus paper turns blue under basic or alkaline conditions, with the color change occurring over the pH range 4.
Neutral litmus paper is purple. Phenolphthalein is often used as an indicator in acid—base titrations. The blue dye has been extracted from lichens since the 16th century.
The word "litmus" comes from the old Norse word for "dye" or "color. While all litmus paper acts as pH paper, the opposite is not true. It's incorrect to refer to all pH paper as "litmus paper.
To perform the test, place a drop of liquid sample on a small strip of paper or dip a piece of litmus paper in a small specimen of the sample. Ideally, don't dip litmus paper in an entire container of a chemical—the dye could contaminate a potentially valuable sample. The litmus test is a quick method of determining whether a liquid or gaseous solution is acidic or basic alkaline.
The test can be performed using litmus paper or an aqueous solution containing litmus dye. Initially, litmus paper is either red or blue. The blue paper changes to red, indicating acidity somewhere between the pH range of 4. Note that 8. Red litmus paper can indicate alkalinity with a change to blue. In general, litmus paper is red below a pH of 4.
If the paper turns purple, this indicates the pH is near neutral. Red paper that does not change color indicates the sample is an acid. Blue paper that does not change color indicates the sample is a base.
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