Which substance is most likely to have a bitter taste?

1) NaOH(aq)
2) NaCl(aq)
3) HCl(aq)
4) None of the above

1. NaOH(aq) is the substance of the following that tastes bitter.

Explanation:

NaOH is commonly called Caustic Soda . The threshold for taste was determined to be 0.008 mole/liter. Some says that the taste is “soapy” since a taster would experience the hard soap occurring in the mouth and experience a bitter taste.

In your mouth, you have plenty of fat, mostly in the form of cell membranes. As such, when you imbibe NaOH it reacts with the fat in your mouth to form soap. A bitter taste is your body's way of saying, don't eat that.