72.
Litmus is obtained from

73.
The pH of lemon juice is expected to be

74.
Antacids are found in drugs that give relief to

76.
Sour taste of lemon is due to the presence of which of the following ?

77.
pH scale ranges from

79.
Which one of the following is used as preservative for foodstuff ?

80.
The acid which fails to liberate carbon dioxide from sodium bicarbonate is :