What's the pH of HCL present in our stomach ?

it is 1. 4 in stomach it is consentrated

Explanation:

1.5 to 3.5

Parietal cells contain an extensive secretory network (called canaliculi) from which the hydrochloric acid is secreted into the lumen of the stomach. The pH of gastric acid is 1.5 to 3.5 in the human stomach lumen, a level maintained by the proton pump H+/K+ ATPase.

altitude, density, pressure

air gets less dense the higher the altitude and also the air pressure is less as altitude rises.

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.