Science, asked by aryajhanak19, 1 year ago

please give me school notes of acid bases and salt tommorow. is my paper urgent

Answers

Answered by yogeshshivhare
1
Acids Bases

a) Taste of acids is sour. a) Taste of bases is bitter.
b) Acids turn blue litmus paper into red. b) Bases turn red litmus paper to blue.
c) Acids contain H+ ( hydrogen ion) c) bases contain OH- ( hydroxyl ion)


Q -2) Ammonia is found in many household products, such as window cleaners. It turns red litmus paper blue. What is its nature?

Ans.) Ammonia is having a basic nature.



Q-3) Name the source from which litmus solution is obtained. What is the use of this solution?

Ans.) Litmus solution is extracted from lichens and is used to determine whether the given solution is basic or acidic.



Q-4) Is distilled water acidic or basic or neutral? How would you verify it?

Ans.) Distilled water is neutral. One can verify it by showing that neither red nor blue litmus paper changes its colour when dipped in distilled water.



Q-5) Describe the process of neutralization with the help of an example.

Ans.) The reaction which occurs between acid and base is known as neutralization. Salt and water are by-products in this process and heat is also liberated.

Magnesium hydroxide, baking soda, etc. which contain bases are used to reduce acidity in our stomach.

Q-6) Mark “t” if the statement is true and “f” if it is false:

a) Nitric acid turns red litmus paper into blue. (t/f)
b) Sodium hydroxide and hydrochloric acid neutralise each other and form water and salt. (t/f)
c) Sodium hydroxide turns blue litmus paper into red. (t/f)
d) Tooth decay is caused by the presence of a base. (t/f)
e) Indicator is a substance which shows different colours in basic and acidic solution.
Ans.) (a) f (b) t (c) f (d) f (e) t



Q-7) Dorji has a few bottles of soft drink in his restaurant. But, unfortunately, these are not labelled. He has to serve the drinks on the demand of the customers. One customer wants an acidic drink, another wants a basic and third one wants a neutral drink. How will Dorji decide which drink is to be served to whom?



Ans.) Dorji can decide this with the help of a litmus paper

a) If blue litmus turns into red when dipped in the drink, then the drink is acidic.
b) If red litmus turns into blue when dipped in the drink, then the drink is basic.
c) If the colour of litmus paper does not change when dipped in the drink, then the drink is neutral.


Q-8) Explain why:

1) An antacid tablet is taken when you suffer from acidity.

2) Factory waste is neutralised before disposing it into the water bodies.

3) Calamine solution is applied on the skin when an ant bites.

Ans.)

1) We take an antacid like magnesium hydroxide to neutralise the extra acid which is released in our stomach.

2) The waste which comes from factories contains acid, and if this acid is dumped into the water body, it harms the organisms present in it. So it is necessary to neutralise this waste by adding a basic substance.

3) Ant injects Formic acid (an acidic liquid) into the skin by biting our skin which causes inflammation of the skin. The effect of the acid can be neutralised by rubbing the skin with Calamine solution which contains a weak base like zinc carbonate so that it causes no harm to the skin.



Q-9) Three liquids are given. One is hydrochloric acid, another is sugar solution and third is sodium hydroxide. How will you identify them? You have only a turmeric indicator.

Ans.)

Name Effect on turmeric indicator

Hydrochloric acid Yellow to blue

Sugar Solution No change

Sodium Hydroxide Yellow to red



Q-10) Blue Litmus paper is dipped in a solution. It remains blue. What can be said about the nature of the solution? Explain.

Ans.)

a) When litmus paper is dipped into a basic solution, it turns blue. Here, as the colour of the litmus paper is not changed or affected, the given solution is basic in nature.

b) Even when the solution is neutral, the colour of the litmus paper will not change.
Answered by aishowrya
1
heya!!

Here are the notes of ACID, BASES AND SALT !!

ACID: Taste of acid is sour. There are many substances that contain acid and so taste sour.

For example – lemon, curd, pickles, orange juice, vinegar, etc.

The chemical nature of such substance is known as ACIDIC.

The word acid comes from Latin ‘ACERE’ which means sour.

BASE: Taste of base is bitter. Substances that contain base taste bitter.

For example; soap or soap solution, baking soda, washing soda, etc.

The chemical nature of substances that contain base is known as BASIC.

INDICATOR: A substance which detects the acidic or basic nature of another substance by change in colour is called an indicator. acid-base indicators are used to check if a given substance is acid or base.

Indicators can be divided into two types.

Natural Indicator: Indicators that are obtained from naturally occurring substance are called NATURAL INDICATORS.

Example: litmus, turmeric, China rose, etc.

Synthetic Indicator: Indicators that are made in laboratory are called SYNTHETIC INDICATORS.

Example: phenolphthalein, methyl orange, etc.

Acid Rain: Carbon dioxide, sulphur dioxide and nitrogen dioxide which are released from vehicles and chimneys mix with droplets of rain and turn the rain water acidic.

When this acidic rain water falls over earth, it is known as acid rain. Acid rain damages the buildings and is harmful for plants and animals.

Characteristics of Acid:

Sour in taste.

Turns blue litmus paper red.

Turns the solution of China rose to dark pink colour (magenta).

Characteristics of BASE:

Bitter in taste.

Turns red litmus paper blue.

Turns solution of China rose to green.

Turns turmeric paper to red

Neutralisation:

Its a chemical process in which salt is formed when an acid and a base is added in equal amount. In this process the involvement of heat is also there.

ACID + BASE => Salt and water ( heat involved )

HCL + NaOH => Nacl + H2O

#hope it helps..!!
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