Page 13 - 10-Chem-10 Acid, Bases and Salts

10. Acid, Bases and Salts eLearn.Punjab

1. When acids react with carbonates and bicarbonates, which gas evolves ?
2. Which types of salts produce SO2 gas on reacting with acids?
3. Give the uses of sulphuric acid.
4. Name the gas liberated when alkalies react with ammonium salts.
5. Write down the colours of the precipitates formed by reaction of aqueous

caustic soda with solutions of: copper, zinc and ferric salts.
6. Name an alkali used in alkaline batteries.

Stomach acidity
Stomach secretes chemicals in a regular way to digest food. These
chemicals mainly consist of hydrochloric acid along with other salts. Although,
hydrochloric acid is highly corrosive, but stomach is protected from its effects
because it is lined with cells that produce a base. The base neutralizes stomach
acid. The important function of this acid is to break down chemical bonds of
foods in the digestion process. Thus, big molecules of food are converted into
small ones. It also kills the harmful bacteria of certain foods and drinks.
However, sometimes stomach produces too much acid. It causes stomach
acidity also called hyperacidity. Symptoms of this disease are feeling burning
sensation throughout the gastro intestinal track. These feelings sometimes
extend towards the chest, that is called heart burning.
The best prevention from hyperacidity is:
i) Avoiding over-eating and staying away from fatty acids and spicy foods.
ii) Simple and regular eating, remaining in an upright position for about 45
minutes after taking a meal.
iii) Keeping the head elevated while sleeping.

Process of Etching in Art and Industry:
The process of etching on glass is carried out by using a wax stencil. Stencil is placed
on areas of glass or mirror that are to be saved from acid. The glass or mirror is
dipped into hydrofluoric acid. The acid dissolves the exposed part of the glass thus
etching it. This process has been very dangerous because the acid would damage the
skin and tissue of artist’s body. Although, it is dangerous to deal with acid, yet etching
done with acid is very attractive as compared to using other chemicals.

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