APES - Water Hardness Quiz

Calcium and Magnesium

Typically causes water to be hard.

Well water

Typically has lots of dissolved minerals as water slowly seeps down through the ground, making it quite "hard"

Limestone

Water that moves through this type of bedrock is often quite "hard" because it is rich in calcium carbonate.

Evaporation

When water does this, the process leaves all of the dissolved substances/minerals behind.

Sudsing

People with hard water often have trouble doing this with soap.

Calcium carbonate

The white scale that often accumulates in humidifiers, tea kettles, and on aquariums is actually composed of this.

Mercury, copper, and lead

When water is artificially softened, heavy metals like these could become more poisonous to fish.

Plastic measuring tube

Name of laboratory equipment used to obtain the correct amount of water to be evaluated in the investigation.

Drops of titrant reagent

These equal the hardness of the water sample in gpg (grains per gallon)

White residue

When these form spots on glasses it is often good evidence that you have hard water.

Blue

We knew that the end point of the titration was complete when the solution turned this color.

Pink

The color the solution turned after added one level measure of Univer Hardness Reagent.

Dropping pipette

Must always be held vertically.

Size of drops

This is dependent on how you hold the dropping pipette.

Water softening device

What is used to remove the compounds that cause hard water.

500 ppm

Hardness values above this level may be hazardous to human health.

Hardness in ppm

To obtain this value you must multiply the number of drops by 17.1.

GPG

Stands for grains per gallon.

Ice Mountain water

Has a hardness value higher than tap water.

Purified water

Often has a hardness value lower than tap water.

Rainwater

Typically has a hardness value close to zero.

Salty

Water softeners can make the soft water taste salty and may be not a great choice for people on low sodium diets.

Lakes

People rarely use soap here to clean up because the water is hard and soap doesn't lather (suds) well.

Soap curds

Often found as a bathtub "ring" in areas with hard water.

Tough and stringy

If hard water is used to preserve vegetables the result can be be this.