Question

4. Give reasons.
a. Glycerine is known as a negative catalyst.
b. Paper burns to ash is a chemical change.
Acid base reaction is also called a neutralization reaction
d. Physical change is a temporary change.

sahi answers dena..
​

Answer 1

Answer:

b. Paper burns to ash is a chemical change because after burning paper cannot be prepared again after once it has been converted into ash. That's why it is called Chemical Change.

c. Acid base reaction is also called neutralisation reaction because after their reaction the product which is produced is not acidic nor basic making the product neutral. That's why it is called neutralisation reaction.

d. Physical change is a temporary change because the thing which has gone under a physical change can again be reversed to its original state. That's why physical change is a temporary change.

hope it helps..

please give thanks..

Answer 2

Answer:

Hydrochloric acid constitutes the majority of gastric acid, the human digestive fluid. In a complex process and at a large energetic burden, it is secreted by parietal cells (also known as oxyntic cells). These cells contain an extensive secretory network (called canaliculi) from which the HCl is secreted into the lumen of the stomach. They are part of the epithelial fundic glands (also known as oxyntic glands) in the stomach. The chemical compound hydrochloric acid is the aqueous (water-based) solution of hydrogen chloride gas (HCl). It is a strong acid, the major component of gastric acid and of wide industrial use. Hydrochloric acid must be handled with appropriate safety precautions because it is a highly corrosive liquid. Hydrochloric acid, or muriatic acid by its historical but still occasionally used name, has been an important and frequently used chemical from early history and was discovered by the alchemist Jabir ibn Hayyan around the year 800. Hydrogen chloride, also known under the name HCl, is a highly corrosive and toxic colorless gas that forms white fumes on contact with humidity. These fumes consist of hydrochloric acid which forms when hydrogen chloride dissolves in water. The hydrogen chloride molecule HCl is a simple diatomic molecule consisting of a hydrogen atom H and a chlorine atom Cl connected with a covalent single bond. Since the chlorine atom is much more electronegative than the hydrogen atom, the covalent bond between the atoms is quite polar. Hydrogen chloride forms corrosive hydrochloric acid on contact with body tissue. Inhalation of the fumes can cause coughing, choking, inflammation of the nose, throat, and upper respiratory tract, and in severe cases, pulmonary edema, circulatory system failure, and death. Skin contact can cause redness, pain, and severe skin burns. Hydrogen chloride may cause severe burns to the eye and permanent eye damage.