PH

What pH is considered to be neutral?

7 Substances with pH less than 7 are acidic, while substances with pH greater than 7 are basic.

What is a buffer?

A solution to which an acid can be added without changing the concentration of available H+ ions (without changing the pH) appreciably.

What is alkalinity?

Alkalinity is the water's capacity to resist changes in pH that would make the water more acidic. This capacity can also be know as "buffering capacity". The capability of water to neutralize acid.

Are there more or less hydrogen ions at a higher pH level?

At higher pH there are fewer free hydrogen ions.

What's the pH of most natural waters?

Between 6.5 and 8.5

What effects do heavy metals have on pH?

Heavy metals tend to be more toxic at lower pH because they are more soluble and more bio available.

What ion is pH a measure of?

Hydrogen

What state of matter does pH deal with?

Hydrogen

What effect does pH have on aquatic ecosystems?

If the pH shifts too drastically then more sensitive organisms will die causing a loss of biodiversity.

What does pH look like throughout the day?

It's highest at mid afternoon when the sun is up and lowest when the sun is down.

What effects do respiration and decomposition have on pH?

Respiration and decomposition process lower pH. For this reason, pH is higher during daylight hours and during the growing season, when photosynthesis is at it's peak.

What is buffering capacity?

The ability to resist change in pH. It controls the overall range of pH change under natural conditions.

What does a pH sample measure?

The concentration of hydrogen ions.

What determines the original pH of the water?

The geology of the watershed and the original source of water.

Why is pH important in ecosystems?

The pH of water determines the solubility and biological availability of chemical constituents such as nutrients and heavy metals. It also determines whether ecosystems can use these constituents.

What is the greatest natural cause of change in pH in a stream?

The seasonal and daily variation of photosynthesis. Photosynthesis uses up hydrogen molecules, which causes the concentration of hydrogen ions to decrease and therefor the pH increases.

How do buffers buffer?

They essentially absorb the excess H+ ions and protect the body of water from fluctuations.

What is pH?

pH is the numeric scale used to specify the acidity or alkalinity of an aqueous solution.

What is the numerical range of the pH scale?

0-14

If a sample of water has a pH of 2, then what is the hydrogen ion concentration in scientific notation?

1x10^-2M 0.01M