Water and pH Scale

Water and pH Scale

Ms. Dabs

Objective

• Review all components of Water and the pH scale

Let's Review

Multiple Choice

What is the correct chemical formula for water?

• H₂O

• HO₂

• H₂O₂

• ₂H₁O

Multiple Choice

Water is polar. What does that mean?

• it is a molecule with opposite charges on opposite ends

• it is a molecule with no charge

• it is a molecule with identical charges on opposite ends

• it is a molecule with too many protons

Water

Remember Water is the most abundant molecule in our bodies. It is composed of positive and negative ends, which make it a polar molecule.

Fill in the Blanks

Water is composed of hydrogen and oxygen molecules. The hydrogen atom is slightly _____________ while the oxygen atom is slightly _____________.

Water

• The hydrogen atom is slightly positive and the oxygen atom is slightly negative.

• Because of that positive and negative charge water is considered a polar molecule. More specifically, water is a polar covalent molecule.

Properties Of Water

• Cohesion: Water sticking to itself

• Adhesion: Water sticking to other surfaces

• Capillary Action: Water traveling against gravity

• Surface Tension: Water beading up and forming a resistance on the surface

Open Ended

What are the four properties of water that we have discussed?

Multiple Select

These properties of water are involved in surface tension

• Capillary Action

• Cohesion

• Adhesion

• High Specific Heat

Multiple Choice

What word describes when water is attracted to other substances?

• cohesion
• adhesion
• capillary action
• surface tension

Multiple Choice

What two elements make up water?

• Helium and oxygen
• Hydrogen and oxygen
• helium and carbon
• oxygen and carbon

How Do Water Molecules Interact

• Remember when we said that water has a positive and negative end, well that positive hydrogen attracts to a negative oxygen and form what is called a hydrogen bond.

Multiple Choice

What is considered a Hydrogen Bond?

• H-Pb

• H-Fe

• H-O

• All of the above

And NOW Let's Give it UP to the pH Scale

What is the pH scale?

the pH scale is used to specify the acidity or basicity of an aqueous solution. Acid solutions are measured at the lower end of the scale, while basic or alkaline solutions are at the higher end of the scale. the scale ranges from 0 - 14 with neutrals falling at 7.

Multiple Choice

What is the only substance with a neutral pH of 7?

• Milk
• Orange Juice
• Water
• Blood

Multiple Choice

The pH scale is a range from:

• 1-7
• 0-14
• 1-14
• 1-20

pH Scale Explained

• pH of 0 - 6.9 is Acidic (H+ ions)

• pH of 7 is neutral

• pH of 7.1 - 14 is Basic (OH- ions)

Strong Acids

Strong acids have a pH range of 1-3 and produce lots of H+ ions.

Strong Bases

Strong acids have a pH range of 11-14 and produce lots of OH- ions and fewer H+ ions.

Multiple Choice

The pH of a strong base would be:

• 1-2
• 5-6
• 8-9
• 12-13

Multiple Choice

The pH of a strong acid would be:

• 1-2
• 5-6
• 8-9
• 12-13

Multiple Choice

The pH scale measures

• the acidity of a chemical
• the reactivity of a chemical
• the boiling point of a chemical
• the electrical conductivity of a chemical

Multiple Choice

This substance releases OH- into solution

• Acid
• Base
• Neutral

Multiple Choice

Which solution releases H+ in solution?

• Base
• Acid
• Buffer
• Water

Multiple Choice

A(n) _______ is a substance with a pH greater than 7.

• Base
• Acid
• Buffer
• Water

Multiple Choice

A(n) ______ is a substance with a pH less than 7

• Acid
• Alkaline
• Base
• Buffer