Acids & Bases

-by : Allyson & Bridgette-

-Lewis Model

In the lewis theory of acid-base reaction, bases donate pairs of electron and acids accept pairs of electrons.

-Arrhenius Model

According to the Arrhenius model, an acid is any subastance that produces hydrogen ions in a water solution ,and a base is any substance that produces hydroxide ions in a water solution.

-Difference between Strong & Weak...


Strength refers to how well an acid or base separates into ions in water. In a strong acid, most of the molecules break up into solutions. In a weak acid, fewer molecules break up into ions.


A strong base is a base that dissociates completely into a metal ion and hydroxide ion in aqueous solution. A weak base is a base that dissociates only slightly in aqueous solution.

Strong & Weak Examples of Acids & Bases

Strong Acids

-Hydrochloric Acid

-Nitric Acid

-Sulfuric Acid

Weak Acids




Strong Bases

-Lithium Hydroxide

-Sodium Hydroxide

-Potassium Hydroxide

Weak Bases




Chemical & Physical Properties of Acids & Bases


Has a sour taste, it turns blue litmus to red, it turns methyl orange to red , acid are electrolyte and strong acids distroy.


Has a bitter taste, slippery touch and conducts electricity.

How can you tell ?

For acidic...

It changes blue litmus to pink and it will have a pH lower than seven.

For bases...

You can use litmus paper to tell if it is a base by the color. It is higher than seven.


How do you measure the strength?

-On a scale of 1-14 measuring the concentrations of Ph

What is the pH ranges?

Acidic: 0-6

Neutral: 7

Basic: 8-14

Acid Rain...

How is Acid rain formed?

- Acid rain is caused by a chemical reaction that begins with compounds such a sulfur dioxide and nitrogen oxides when released into the air. The substances rise into the air and mix and react with the water and oxygen.


-Acidic water affects the growth and health of fish and other aquatic life, by reducing the pH of the water and impacting the health and breeding success of the fish. Acid rain impacts crop growth and soil structure. It can affect the growth of plants.Acid rain can corrode metal structures and erode cement, limestone and marble buildings.
Acid rain damages trees at high elevations. Can cause an increase in heart and lung conditions (and premature death).

How to improve?

1) clean exhaust pipes.

2) Use energy sources.

3) Restore damaged environments.


What is a indicator?

- An indicator is a large organic molecule that works somewhat like a " color dye".

1) Beets

2) Onions

3) Red Cabbage

Can be used as indicators:

1) Cabbage

2) Rose Petals


The indicators change colour because the chemicals in the indicator and the chemicals of the reactor are reacting with each other creating new chemicals that has a colour.