Question

use the text to compare and contrast acids and bases.
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": The text clearly states "An acid is defined as a chemical compound that has a pH of less than 7.0", so this property belongs to acids.
• For "Taste sour": The text says "An acid tastes tart or sour", so this is an acid property.
• For "Are usually solids": The text mentions "bases are usually solids", so this is a base property.
• For "Change litmus paper to red": The text states "Acids change litmus paper to red", so this is an acid property.

Answer:

• Have a pH less than 7.0: Acids
• Taste sour: Acids
• Are usually solids: Bases
• Change litmus paper to red: Acids