I have these two sentences:
- We can get ammonia by treating ammonium salts with caustic soda or sodium hydroxide.
- We can get ammonia by treating ammonium salts with lime water or calcium hydroxide.
Caustic soda is the common name of sodium hydroxide, while lime water and calcium hydroxide are two different substances. Both the sentences are grammatically and scientifically correct, but they obviously mean quite different things.
In this particular case, I happen to know how to parse either sentence, but what if I get a situation where I cannot recognise whether the first term is a synonym for the second, or a different term entirely?
I did not come up with this question myself, the first sentence is actually given in the standard NCERT textbook of INDIA. Nearly 1.5 million students are studying using this book. Is there a mistake in our book?