Not Acid
Puzzle 11 of Caribbean Getaway Easy Pack
Question is: Not Acid
and the answer is: ALKALI
Word Meaning:
ALKALI — (chemistry) One of a class of caustic bases, such as soda, soda ash, caustic soda, potash, ammonia, and lithia, whose distinguishing characteristics are dissolving in alcohol and water, uniting with oils and fats to form soap, neutralizing and forming salts with acids, turning to brown several vegetable yellows, and changing reddened litmus to blue.
Definitions from Wiktionary.