Acids and Bases DOL 1

The pH scale is used to measure how acidic or basic something is. A pH value lower than 7 indicates a substance is an ______, while a pH value higher than 7 is considered _______.

• acid
• base

• acidic

• basic

• neutral

Pure water is considered _______, with a pH of ___.

• neutral
• 7
• basic

• 0

• acidic

Which of the following sets of properties describes a base?

• pH less than 7, bitter taste, slippery texture, corrodes organic material

• pH greater than 7, sour taste, corrodes metal

• pH greater than 7, bitter taste, corrodes organic material, slippery to touch, turns red litmus paper blue

• pH less than 7, sour taste, corrodes metal, can burn if touched, turns red litmus paper blue

Kiva notices that the ingredients label on her drink includes citric acid. She wonders how the acid affects her drink. Which statement describes a possible effect citric acid could have on the drink?

• It could add a sour flavor to the drink.

• It could make the drink more neutral.

• It could make the drink turn red litmus paper blue.

• It could add a bitter flavor to the water.

Which explanation best describes how litmus paper can be used to test whether a substance is an acid or a base?

• Blue litmus paper turns red in the presence of an acid. Red litmus paper turns blue in the presence of a base.

• Blue litmus paper stays blue in the presence of an acid. Red litmus paper stays red in the presence of the base.

• Blue litmus paper turns red in the presence of a base. Red litmus paper turns blue in the presence of an acid.

• Blue litmus paper turns yellow in the presence of a base. Red litmus paper turns yellow in the presence of an acid.

While exploring the Texas Hill Country, you encounter natural hot springs and measure the water's

pH level in each. The data are recorded in the table.

What conclusions can you draw about the presence of acids and bases in these springs?

Which spring is closest to neutral? Explain your reasoning.