Part 1 - Calculating Ph

ANSWERS

pH and Life

Part 1 - Calculating pH.

Determine the pH of the following hydrogen ion concentrations using the formula below. Then determine if the solution is an acid, base, or neutral.

pH = -log [H+] Example [H+] = 1.0 X10-7= -log [1.0 X10-7]= 7.0 = neutral

1. [H+] = 2.5x10-6 =5.59 = acid
2. [H+] = 6.3x10-8 = 7.2 = neutral
3. [H+] = 1.99x10-10 = 9.7 =base
4. [H+] = 3.16x10-11 = 10.5 =base / 5. [H+] = 0.000316= 3.5 = acid
6.[H+]= 1.58x10-7 = 6.8 = neutral

Part 2- Calculating hydrogen ion concentration.

Determine the hydrogen ion concentrations of the following pH using the formula below.

inverse log -pH = [H+]

1. pH= 4.3 = [H+] = 5.0x10-5
2. pH= 7.9= [H+] = 1.3x10-8
3. pH= 2.6= [H+] = 0.0251
4. pH= 9.8= [H+] = 1.58x10-10 / 5. pH=11= [H+] = 1.0x10-11
6. pH=7= [H+] = 0.0000001

Part 3 – Pond pH

Given below are the pH ranges at which various aquatic organisms can survive. Based on the given hydrogen ion concentrations, determine the pH of each pond. Then use the information below to rank the ponds from best to worst for supporting life and explain why.

pH Ranges that Support Aquatic Life: Below are the normal ranges for various organism and the levels of pH they can live at.

Bacteria: 1.5 to 13.5

Plants: 6.5 to 12.0

Carp, suckers, catfish: 6.0 to 9.0

Bass, crappies: 6.5 to 8.5

Snails, clams, mussels: 7.5 to 9.0

Trout, frogs, aquatic invertebrates*: 6.5 to 7.5

(*most mayfly, stonefly, and caddisfly nymphs; tadpoles)

Little Bass: 2.0x10-9 M= 8.69 pHGlacier: 5.6x10-8 M = 7.25 pH

Antler: 5.62x10-7 M = 6.25 pH Big Bass 3.16 x10-10 M = 9.5 pH

Part 4 – Human Blood pH

The normal blood pH for a human is 7.35-7.45. This narrow range can be affected when various organs are not functioning properly. When a person cannot get rid of the CO2 from their lungs they may become acidotic (pH less than 7.35). If however a person’s kidneys are overproducing sodium bicarbonate they may become alkalotic [basic] (where the pH is greater than 7.45).

Blood was drawn on three patients in the hospital. Below are the concentrations of hydrogen ions found in their blood stream. Determine for each person:

The pH of their blood
If they are normal, acidotic, or alkalotic (basic)
If they should see another doctor (namely a respiratory (lung) doctor or renal (kidney) doctor

Patient / Hydrogen Ion Concentration / pH / pH Term / Doctor?
Mr. Nephros / 7.79 pH = 1.6x10-8
Miss Alveola / 7.14 pH = 7.1x10-8
Mrs. Sanguine / 7.38 pH = 4.1x10-8

pH and Life

Part 1 - Calculating pH.

Determine the pH of the following hydrogen ion concentrations using the formula below. Then determine if the solution is an acid, base, or neutral.

pH = -log [H+] Example [H+] = 1.0 X10-7= -log [1.0 X10-7]= 7.0 = neutral

1. [H+] = 2.5x10-6 =
2. [H+] = 6.3x10-8 =
3. [H+] = 1.99x10-10 =
4. [H+] = 3.16x10-11 = / 5. [H+] = 0.000316=
6. [H+]= 1.58x10-7 =

Part 2- Calculating hydrogen ion concentration.

Determine the hydrogen ion concentrations of the following pH using the formula below.

inverse log -pH = [H+]

1. pH= 4.3 = [H+] =
2. pH= 7.9= [H+] =
3. pH= 2.6= [H+] =
4. pH= 9.8= [H+] = / 5. pH=11= [H+] =
6. pH=7= [H+] =

Part 3 – Pond pH