# Ph Formula

## pH Formula

pH is a measure of the amount of activity of hydrogen ions (H+) in a solution and thus its alkalinity or acidity. Although a pH value is unitless, it is not a random scale; the number rises from a description grounded on the activity of hydrogen ions in the solution. pH is described as “the negative of the logarithm of the molar hydronium-ion concentration.”

pH Formula is arithmetically articulated as

$\dpi{120}&space;\large&space;pH=-log[H_{3}O^{+}]$

The pH Formula can also be noted as

$\dpi{120}&space;\large&space;pH=-log[H^{+}]$

pH Problems

Solved numerical based on pH are provided under.

Problem 1: Calculate the pH of human arterial blood in which the hydronium ion concentration is 4.0 ×× 10-8M.

The concentration of hydronium ion is 4.0 × 10-8M

Thus, we can make use of the formula,

$\dpi{120}&space;\large&space;pH=-log[H_{3}O^{+}]$

pH = – log[4.0 × 10-8]

pH = 7.40

As the hydronium ion concentration is provided till two decimal places we can note the pH with two significant figures.

Problem 2: A brand of carbonated beverage has a pH of 3.16. What is the hydronium ion concentration of the beverage?

The concentration of hydronium ion is

[H3O+] = antilog (-pH) = 10-pH

[H3O+] = antilog (-3.16) = 10-3.16

[H3O+] = 7.0 × 10-4M

#### Practise This Question

Physiological effects of a phytohormone are given below

1. Cell division

2. Removal of apical dominance

3. Delay of senescence

4. Help in stomatal opening

Identify the phytohormone involved in the above processes