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A sample of soil is mixed with water and allowed to settle. The clear supernatant solution turns the pH paper yellowish-orange. Which of the following would change the colour of this pH paper to greenish-blue?
Yellowish orange colour on pH paper is shown by acidic substances hence to change the colour of pH paper to greenish blue (pH = 8), an antacid should be added since antacids are basic in nature.
A fruit juice is tested for its pH value. What could be its possible pH if the colour is changed to yellow?
Less than 6.0
pH range ( 5-6) shows up yellow colour on pH paper.
Which of the following will be the strongest base?
Strong bases have very high pH values, usually in range 12 to 14.
Four student (a), (b), (c) and (d) measured the pH values of water, lemon juice and sodium bicarbonate solution. What is the correct decreasing order of pH values?
1.Sodium bicarbonate (as it is a base and has pH value more than 7) .
2. Water (as it is neutral and has pH value as 7) .
3. Lemon juice (it is acidic and the pH value is less than 7).
Formic acid is also present in a natural state in stinging nettles, and is reponsible for the burning feeling on contact with them. It is also found in the stings and bites of many insects, including bees and ants, which use it as a chemical defence mechanism.
pH of distilled water is:
Pure distilled water should be neutral with a pH of 7, but because it absorbs carbon dioxide from the atmosphere, it's actually slightly acidic with a pH of 5.8.
Tooth decay occurs when pH of mouth is below:
Due to eating more sweets and sugary things the particles of sugar will remain left in our mouth the bacteria present in our mouth causes the degradation of these sugar particles to produce large amount of acid which result in decrease of pH of mouth from 5.5 ultimately it lead to tooth decay.Tooth decay starts when pH is lower than 5.5 this is because the acid attack the enamel of our teeth and corrode it.
A student dipped a pH paper in an unknown liquid. Orange colour was obtained. The unknown solution can be:
Both acetic acid and ethanoic acid can turn the pH paper orange. Sodium carbonate is basic in nature.
A drop of solution ‘X’ is placed on a strip of pH paper. A deep red colour is produced. The solution ‘X’ is:
HCl is a strong acid and has pH = 1 and hence turns the pH paper red.
The pH of a solution which is neither acidic nor basic is:
A solution that is neither acidic nor basic is neutral and has a pH of 7.