Question

IL Fill in the blanks.
1.
is a chemical that changes its colour to indicate the presence of a chemical substance
2.
are substances that have a sour taste.
3. Rain containing excess of acid is called
are substances that taste bitter and feel slippery to the skin.
5.
are examples of naturally occurring indicators
6. When an acidic solution is mixed with a basic solution, they
each other forming
and water
11​

Answer 1

Required Answers:

1. Methyl Orange is a chemical that changes its colour to indicate the presence of a chemical substance.

2. Acids are substances that have a sour taste.

4. Litmus, turmeric paper, china rose are examples of naturally occurring indicators.

5.When an acidic solution is mixed with a basic solution, they each other forming salt and water

______________________________

Explanation :

( a )

→ An indicator is a substance by which we recognize whether the substance is acidic,basic or neutral by its colour change.

Methyl orange is a chemical indicator that changes its colour to indicate the presence of a chemical substance.

In acidic solution it changes it to red.

In base and neutral solutions it changes it to yellow.

( b )

→ Acids are sour is taste as well as soapy in touch.

More-

• There are two types of acids

• Mineral acids

• Organic acids

( d )

→ Natural indicators are those that are obtained from natural substances.They are not made from chemicals.Turmeric is the indicator that is used as tumeric paper, and litmus obtained from lichens and china rose are some examples of naturally occurring indicators.

( e )

When acid and base react with each other ,the chemical reaction is called neutralization.In neutralization process water and salt are formed and heat is evolved.

Base + Acid → Water + Salt + Heat ( evolved )

_______________________________

Answer 2

$\huge\fbox\red{In words}$

1. Methyl Orange

2. Acids

3 . Litmus, turmeric paper, china rose

4 . Salt

$\huge\fbox\red{In sentence :-}$

1. Methyl Orange is a chemical that changes its colour to indicate the presence of a chemical substance.

2. Acids are substances that have a sour taste.

3 . Litmus, turmeric paper, china rose are examples of naturally occurring indicators.

4 .When an acidic solution is mixed with a basic solution, they each other forming salt and water