Which of the following liquids are likely to have a pH less than 7, indicating they are acidic? Select all that apply.

Acidic liquids are those that give a sour taste, turn red litmus paper blue, or dissolve metal filings. Common household liquids that are acidic include vinegar (acetic acid), lemon juice (citric acid), soda (carbonic and phosphoric acids), and coffee (caffeine and organic acids). Each of these contains enough dissolved acid to lower the pH below 7, while neutral liquids like tap water or milk stay near pH 7. For example, a drop of vinegar will turn a drop of red litmus paper blue, confirming its acidity. Thus, vinegar, lemon juice, soda, and coffee are the liquids likely to have a pH less than 7.