Question

use the text to compare and contrast bases and acids. an acid is defined as a chemical compound that has a ph of less than 7.0. a base is the chemical opposite of an acid; it has a ph of greater than 7.0. to better understand the two, it can help to think of some household examples. an acid tastes tart or sour; vinegar and lemon juice are both acids. by contrast, a base tastes bitter; soap and baking soda are good examples. depending on the temperature, acids can be in solid, liquid, or gaseous form, whereas bases are usually solids. when conducting experiments, a chemist may perform a litmus test to determine whether a compound is an acid or base. acids change litmus paper to red, while bases cause litmus paper to turn blue.

Explanation:

• For "Have a pH less than 7.0": According to the text, acids have a pH less than 7.0, so check the acid column.
• For "Taste sour": The text states that acids taste tart or sour, so check the acid column.
• For "Are usually solids": The text says bases are usually solids, so check the base column.
• For "Change litmus paper to red": The text mentions acids change litmus paper to red, so check the acid column.

Answer:

• Have a pH less than 7.0: Check the acid column.
• Taste sour: Check the acid column.
• Are usually solids: Check the base column.
• Change litmus paper to red: Check the acid column.