Determining pH of Household Items

Teaching Strong/Weak Acids and Bases

through Inquiry and Observation

Auburn R. James

Applying Major Units in Chemistry to

Everyday Life

Acids

-soda

-clothing dye

-stomach acid

Bases

-soap

-cleaning supplies

-toothpaste

Salts

-table salt

-pool treating supplies

-baking soda

Encountered in Everyday Life

http://whatafy.com/who-discovered-sulfuric-acid.html

http://www.pacoa.com/austin-521-clear-ammonia-00052.html

http://www.amerimerc.com/pool-chlorine~granular-chlorine.htm

Active Participation Throughout

Acid/Base/Salt Units

Students are asked to bring items from home that they think are classified as an acid, base or salt (each unit can focus on one of

the categories)

Students identify why they hypothesize this material falls into that catergory

(cleaning supplies containing ammonia feels soapy, soda tastes acidic)

Material is tested.

The pH is determined using a probe, reactivity

with chemicals is compared to that of known

acids/bases and salts.

What did the student learn through observation?

Were they right? What is the identity of the chemical

in the item they brought in?

Calculations are performed—what is the pKa of the acid in Coke?

Results are written up and presented,

Highlights of Lesson, Why is it

Engaging?

Hands on laboratory

study

Students are required to think about materials’

properties to decide which to bring in

Observe and compare

properties of household items

to laboratory chemicals

Practice using pH probes

Lesson supports

group work

Identify substance by data collected: data processing and calculations

Applies science to everyday

life

http://www.geminibv.nl/labware/metrohm-704-ph-meter-1/