Question

Q. (a) Mention the pH range within which our body works. Explain how antacids
give relief from acidity. Write the name of one such antacid.
(b) Fresh milk has a pH of 6. How does the pH will change as it turns to curd? Explain your answer.
(c) A milkman adds a very small amount of baking soda to fresh milk. Why does this milk take a longer time to set as curd?
(d) Mention the nature of toothpastes. How do they prevent tooth decay?

Answer 1

a) antacid react with HCl(which cause acidity) present in our stomach to give neutral .e.g.-NAHCO3(sodium bicarbonate).
b) bacteria present in milk turn milk into curd and decrease it's pH.
c)milkman increase it's pH and it's him to get longer time to turn into curd .
d)toothpaste is basic in nature.and it react with acid present in our mouth to give neutral.

Answer 2

pH range = 7.0-7.1
A. as antacids are basic in nature, it neutralises effect of acids in our stomach hence reducing intense pain
B. as milk turns into curd, it's pH will fall below 6. this is because an acid is produced when milk turns into curd
C. the slightly acidic milk takes a longer time to set as curd because the lactic acid being produced during curdling has to first neutralise the alkali present in it
D. toothpastes are basic in nature and during tooth decay access of acids in present in our Mouth and toothpaste neutralises the effect of access acids