Read the list of common household substances. Antacid, orange juice, toothpaste, vinegar Which of these substances are likely to have a bitter taste? Antacid, vinegar Antacid, toothpaste Orange juice, vinegar Orange juice, toothpaste

The correct answer is antacid, toothpaste.

Note: I assume the options are:

Antacid, vinegar Antacid, toothpaste Orange juice, vinegar Orange juice, toothpaste

Acids are those chemicals which release hydrogen ions in aqueous solution.

They change the color of litmus paper to blue and taste sour. They react with metals and release hydrogen gas. For example, HCl, citric acid (found in citric fruits such as oranges, lemons etc), carbonic acids. acetic acid (vinegar).

In contrast, bases are those chemicals which release hydroxide ions in aqueous solution.

They change the color of litmus paper to blue and taste bitter. For example, calcium hydroxide, sodium hydroxide, etc. Antacids are also basic in nature and thus they are bitter in taste. In addition, pH of commercial toothpastes is also kept as slightly basic as acidic pH can corrode the enamel of the teeth. Hence, it would taste bitter in absence of artificial flavors.