Advertisements
Advertisements
Question
What damage could be caused while the pH is low?
Solution
When the pH in the mouth falls to around 5.5, tooth decay begins. As the acidity in the mouth increases, the acid reacts with the tooth enamel and causes tooth decay.
APPEARS IN
RELATED QUESTIONS
Three liquids are given to you. One is hydrochloric acid, another is sodium hydroxide and the third is a sugar solution. How will you identify them? You have only turmeric indicator.
Why should curd and other sour foodstuffs (like lemon juice, etc.) not be kept in metal containers (such as copper and brass vessels)?
Name the scientist who developed the pH scale.
The pH of soil A is 7.5 while that of soil B is 4.5. Which of the two soils, A or B, should be treated with powdered chalk to adjust its pH and why?
Under what soil conditions do you think a farmer would treat the soil of his fields with quicklime (calcium oxide), or slaked lime (calcium hydroxide) or chalk (calcium carbonate)?
Solution A turns universal indicator blue to purple whereas solution B turns universal indicator orange to red.
Name any two substances which can give solutions like A.
A group of students measured the pH of some substances they found in their homes. Their results are given in the following table:
Substance | pH | Substance | pH |
Apples | 3.0 | Salt | 7.0 |
Baking soda | 8.5 | Sugar | 7.0 |
Black coffee | 5.0 | Toothpaste | 9.0 |
Household ammonia | 12.0 | Vinegar | 3.0 |
Lemon juice | 2.5 | Washing soda | 11.5 |
Milk | 6.5 |
(a) What would the students have used to measure the pH?
(b) Which solution is the most acidic?
(c) Which solution is the most alkaline?
(d) Which solutions are neutral?
(e) Which solution can be used to treat wasp stings?
(f) Which solutions can be used to treat bee stings?
How will you prepare natural indicator from turmeric powder?
Write a note on:
Phenolphthalein
A milkman adds a very small amount of baking soda to fresh milk. Why does this milk take a long time to set as curd?