Question

What is COD? Which chemical substance is generally used in its measurement?

Answer 1

The specific heat of a body is defined as the quantity of heat required to raise the temperature of unit mass of a body through one degree Celsius.

S=Q/m ΔT

To determine the specific heat of solids usually the method of mixtures is followed.
In method of mixtures, specific heat of either a solid or a liquid is determined.

The method of mixtures obeys the fundamental principle of calorimetry.

Heat lost by hot bodies= Heat gained by cold body

Answer 2

The abbreviation for COD is chemical oxygen demand. Generally, a "0.25 N" solution of "potassium dichromate" is used for "COD determination". For water samples whose COD is below "50 mg/L", a "lower concentration" of "potassium dichromate" is usually preferred. This term is used to determine the oxygen presence in water. It is also used to define the quantity of the organic water.