Monday 4/29 Check In

Open Ended

How was your weekend? Share what you did and what your goals are for this week--either personal, school-related or BOTH. Complete answers will receive PBIS points.

Acids, Bases with Natural pH indicator

​Purple cabbage can be boiled in water to use as a natural indicator!

Properties of Acids

• Taste sour.

• React with metals.

• They are corrosive.

• Formulas begin with "H". (example HCl)

Multiple Choice

Acids taste

• bitter

• sour

• sweet

• salty

Acids

• All fruits and most vegetables are acidic.

Strong Acids

• Strong acids are used chemical reactions to create certain products.

Multiple Choice

Strongest acids have a pH of

• 1

• 4

• 6

• 7

Bases

• Taste bitter

• Feel slippery.

• React with metals

• They are corrosive

Multiple Choice

Bases taste

• bitter

• sour

• sweet

• salty

Bases

• Many bases contain the hydroxide ion (OH^-).

• They are used as cleaners.

• They damage living tissue and bacteria.

  
  

Strong Bases

• Are used as drain cleaners and disinfectants.

Bases and pH

• Strong bases have a pH between 12 and 14.

• Weak bases have a pH between 7 and 12

• Bases are referred to as "alkaline".

Multiple Choice

Strong bases have a pH of

• 1

• 4

• 9

• 13

The pH Scale

• Measures the potential for hydrogen ions (H⁺) or (H₃O⁺) to form.

• The scale goes from 0 to 14.

• Acids are less than 7.

• Bases are greater than 7.

• A pH of 7 is neutral.

Multiple Choice

7 on the pH scale means a liquid is

• an acid

• a base

• neutral

• corrosive

Strength of Acids

• As you move away from a pH of 7, the acid strength increases.

• Each number increases by a power of 10

• A pH of 6 is 10 times stronger than 7.

• A pH of 5 is 100 times stronger than 7

Multiple Choice

How much stronger is an acid with a pH of 2 compared to an acid with a pH of 4?

• 10 x

• 100 x

• 1000 x

• 10,000 x

Answer

There is a difference of 4. The power of 10⁴ equals 10,000.

Multiple Choice

How much stronger is an acid with a pH of 2 compared to an acid with a pH of 6?

• 10 x

• 100 x

• 1000 x

• 10, 000 x

Strength of Bases

• As you move away from a pH of 7, bases increase in strength.

• A pH of 8 is 10 times greater than 7

• A pH of 9 is 100 times greater than 7.

• A pH of 10 is 1000 times greater than 7.

Multiple Choice

How much stronger is a base with a pH of 10 compared to a base with a pH of 9?

• 10 x

• 100 x

• 1000 x

• 10,000 x

Multiple Choice

How much stronger is a base with a pH of 12 compared to a base with a pH of 9?

• 10 x

• 100 x

• 1000 x

• 10,000 x

Neutralization Reaction

• When equal amounts and equal strengths of an acid and a base are mixed together, the liquids will neutralize.

• The result will have a pH of 7

• The products are water (H₂O) and a type of salt (NaCl)

• 
  

Multiple Choice

What is the pH of a solution that is neutral?

• 1

• 5

• 7

• 9

Multiple Choice

According to the image, the substance tested is a...

• Acid
• Neutral
• Strong Acid
• Base

Multiple Choice

According to the image, the substance tested is a...

• Acid
• Base
• Neutral
• Strong Acid

Red cabbage juice is used as a natural pH indicator

​

Natural pH indicator
Red Cabbage Juice

Multiple Choice

One benefit of Red Cabbage Juice Indicator is that it...

• Tells you the exact pH 
• Is very accurate
• It is very expensive
• It can be made from materials you have at home

Poll

Do you know how to read and measure the pH scale using different indicators?