Basic-acid dosage

What is a dosage ?
Is to determine the amount of a chemical species.

how to make dosage?

hydrochloric acid assayed by a sodium hydroxide solution 
It is necessary to determine the concentration of the hydrochloric acid 
we will take a precise volume of solution (H+Cl-) 
to detect equivalence poured bromothymol blue.

Evolution of pH during dosage 

It is noted that the color is yellow at the start so that there is no acid,
then poured soda thus increasing pH (because disappearance of H + ions),
the solution turns blue, therefore the pH thereof is neutral,
it is called equivalence.
 

Alkanes

Alkanes are composed of carbon atoms and hydrogen atoms. Linear alkanes have the molecular formula CnH2n+2. Alkanes exist largely as a gas. As all hydrocarbons, they are insoluble in water.

Combustions

This year, we studied the chimic energy in particular the combustion. We are going to present this chapter.

A combustion is a chemical transformation which produces heat. To have a combustion you need  : a fuel (wood, gas...), a combustive (air) and a source of heat. To stop a combustion it is enough to supress one of the sides of the triangle of the fire.

It exist two types of combustions : complete combustion (air in sufficiency, blue flame); incomplete combustion (incapacity of dioxygene, orange flame).