What does 溶液 mean?
溶液 is a Japanese noun meaning “solution” in English. It is written as 溶液 in kanji, ようえき in hiragana, and youeki in romaji. This word is part of JLPT N1 vocabulary.
Example sentence
リトマス紙で溶液の液性（酸性、中性、塩基性）を調べるときは、リトマス紙をすべて溶液に浸すのではなく、紙の先端の部分だけを浸します。
When investigating the pH (acidic, neutral, alkaline) of a liquid, don't soak the litmus paper completely in the liquid but just put the end of the paper in it.