Water Properties, Acids, Bases, Buffers, and Reactions

Flashcards covering properties of water, acids, bases, buffers, and types of chemical reactions.

What phenomenon allows a paperclip to float on water?

Surface tension

What phenomenon allows a water strider to glide on water?

Surface tension

What happens when a covalent bond within a water molecule breaks spontaneously?

It produces a positive hydrogen ion (H+) and a negative hydroxide ion (OH-).

What ions are produced when a water molecule dissociates?

A positive hydrogen ion (H+) and a negative hydroxide ion (OH-).

What is the pH of pure water?

7

What is true about the concentrations of [H+] and [OH-] in pure water?

There are equal amounts of [H+] relative to [OH-].

How is an acid defined in terms of H+ concentration?

Any substance that dissociates in water and increases the [H+].

What pH values do acidic solutions have?

pH values below 7.

How is a base defined in terms of its interaction with H+?

Any substance that combines with [H+] to remove [H+] from solution.

What pH values do basic solutions have?

pH values above 7.

What do bases often add to solutions?

OH-

What is the function of a buffer?

It removes both acids (H+) and bases (OH-) from solution.

What key characteristic do buffers have regarding pH changes?

They resist changes in pH.

What common household substance is given as an example of a buffer?

Baking soda.

What is the chemical name for baking soda?

Sodium bicarbonate (NaHCO3).

What type of reaction gives off heat?

An exothermic reaction.

What type of reaction absorbs heat?

An endothermic reaction.