Question

: _______ tastes sour.
(A) Curd, lemon juice
(B) Orange juice
(C) Vinegar
(D) All of the above

Answer 1

Hint:According to the question, first we have to check the given substances, chemical properties or composition. If any of the given substances contains acid, then it will taste sour.

Complete answer:As we know, acidic substances taste sour because an acid is a substance that donates hydrogen ions, due to this, in an acidic solution there are more hydrogen ions than hydroxide ions. This means the more advice a food is, the more hydrogen ions are available to trigger the sour tastes receptors.
As we know, curd is made by fermentation process, in fermentation process, when lactobacillus bacteria added to the milk, then they convert the lactose sugar that is present in the milk into the lactic acid and it is the lactic acid which makes curd sour in taste. And for lemon juice, we all know lemon contains citric acid, and acid tastes sour. So due to citric acid, lemon juice tastes juice sour.
Similarly, Orange juice contains citric acid, and acid tastes sour. So due to citric acid, orange juice tastes juice sour.
And, Vinegar is also known as an Acetic Acid. And acid's behaviour is to taste sour. So, vinegar also tastes sour.
So, all the substances in the options contain acid and taste sour.

Hence, the correct option is (D), All of the above.

Note: It should be remembered that sometimes curd tastes bitter if the fermentation is in excess than the required amount. During the fermentation process, the lactose present in milk is converted to lactic acid under ambient environmental conditions and when optimum consistency is reached then to stop the process it has to be refrigerated. And the fermentation continues and more lactic acid is produced and turns the curd bitter.