Solution B

Solution A

The hand is washed immediately with plenty of water

r and a paste of sodium hydrogencarbonate (a base)

is applied to neutralise the acid

The hand is washed immediately with plenty of water

r and a paste of sodium hydrogencarbonate (a base)

is applied to neutralise the acid

The hand is washed immediately with plenty of water

r and a paste of sodium hydrogencarbonate (a base)

is applied to neutralise the acid

Baking soda solution because it is a base

and hence neutralises the excess acid present in the stomach

Baking soda solution because it is a base

and hence neutralises the excess acid present in the stomach

hydrochloric acid

acetic acid

Water

hydrochloric acid

acetic acid

Water

hydrochloric acid

acetic acid

Water

Importance of pH in everyday life human body works within the pH range of 7 to 7.8

Living organisms can survive only in a narrow range of pH.

When pH of rainwater is less than 5.6 it is called acid rain.

When acid rain flows into the rivers it lowers the pH of the river water

Plants require a specific pH range for their healthy growth

pH in our digestive system stomach produces hydrochloric acid

Living organisms can survive only in a narrow range of pH.

When pH of rainwater is less than 5.6 it is called acid rain.

When acid rain flows into the rivers it lowers the pH of the river water

Plants require a specific pH range for their healthy growth

pH in our digestive system stomach produces hydrochloric acid

It helps in the digestion of food without harming the stomach during indigestion

When pH of rainwater is less than 5.6 it is called acid rain.

When acid rain flows into the rivers it lowers the pH of the river water

Plants require a specific pH range for their healthy growth

pH in our digestive system stomach produces hydrochloric acid

It helps in the digestion of food without harming the stomach during indigestion

The stomach produces too much acid and this causes pain and irritation

When acid rain flows into the rivers it lowers the pH of the river water

Plants require a specific pH range for their healthy growth

pH in our digestive system stomach produces hydrochloric acid

It helps in the digestion of food without harming the stomach during indigestion

The stomach produces too much acid and this causes pain and irritation

To control this pain, people use bases called antacids

Plants require a specific pH range for their healthy growth

pH in our digestive system stomach produces hydrochloric acid

It helps in the digestion of food without harming the stomach during indigestion

The stomach produces too much acid and this causes pain and irritation

To control this pain, people use bases called antacids

These antacids neutralize the excess acid

pH change as the cause of tooth decay: tooth decay starts when the pH of the mouth is lower than 5.5.

It helps in the digestion of food without harming the stomach during indigestion

The stomach produces too much acid and this causes pain and irritation

To control this pain, people use bases called antacids

These antacids neutralize the excess acid

pH change as the cause of tooth decay: tooth decay starts when the pH of the mouth is lower than 5.5.

Tooth enamel is made up of calcium phosphate is the hardest substance in the body

The stomach produces too much acid and this causes pain and irritation

To control this pain, people use bases called antacids

These antacids neutralize the excess acid

pH change as the cause of tooth decay: tooth decay starts when the pH of the mouth is lower than 5.5.

Tooth enamel is made up of calcium phosphate is the hardest substance in the body

It does not dissolve in water but is corroded when the pH in the mouth is below 5.5

To control this pain, people use bases called antacids

These antacids neutralize the excess acid

pH change as the cause of tooth decay: tooth decay starts when the pH of the mouth is lower than 5.5.

Tooth enamel is made up of calcium phosphate is the hardest substance in the body

It does not dissolve in water but is corroded when the pH in the mouth is below 5.5

Bacteria present in the mouth produce acids by degradation of sugar and food particles remaining in the mouth after eating

These antacids neutralize the excess acid

pH change as the cause of tooth decay: tooth decay starts when the pH of the mouth is lower than 5.5.

Tooth enamel is made up of calcium phosphate is the hardest substance in the body

It does not dissolve in water but is corroded when the pH in the mouth is below 5.5

Bacteria present in the mouth produce acids by degradation of sugar and food particles remaining in the mouth after eating

The best way to prevent this is to clean the mouth after eating food

Some Naturally-Occurring Acids: Acetic acid from vinegar, citric acid from orange, and lemon, tartaric acid from tamarind; oxalic acid from tomato, lactic acid from sour milk (curd), aceticc acid from and sting and nettle sting

Tooth enamel is made up of calcium phosphate is the hardest substance in the body

It does not dissolve in water but is corroded when the pH in the mouth is below 5.5

Bacteria present in the mouth produce acids by degradation of sugar and food particles remaining in the mouth after eating

The best way to prevent this is to clean the mouth after eating food

Some Naturally-Occurring Acids: Acetic acid from vinegar, citric acid from orange, and lemon, tartaric acid from tamarind; oxalic acid from tomato, lactic acid from sour milk (curd), aceticc acid from and sting and nettle sting

Tooth enamel is made up of calcium phosphate is the hardest substance in the body

It does not dissolve in water but is corroded when the pH in the mouth is below 5.5

Bacteria present in the mouth produce acids by degradation of sugar and food particles remaining in the mouth after eating

The best way to prevent this is to clean the mouth after eating food

Some Naturally-Occurring Acids: Acetic acid from vinegar, citric acid from orange, and lemon, tartaric acid from tamarind; oxalic acid from tomato, lactic acid from sour milk (curd), aceticc acid from and sting and nettle sting

Tooth enamel is made up of calcium phosphate is the hardest substance in the body

It does not dissolve in water but is corroded when the pH in the mouth is below 5.5

Bacteria present in the mouth produce acids by degradation of sugar and food particles remaining in the mouth after eating

The best way to prevent this is to clean the mouth after eating food

Some Naturally-Occurring Acids: Acetic acid from vinegar, citric acid from orange, and lemon, tartaric acid from tamarind; oxalic acid from tomato, lactic acid from sour milk (curd), aceticc acid from and sting and nettle sting

Tooth enamel is made up of calcium phosphate is the hardest substance in the body

It does not dissolve in water but is corroded when the pH in the mouth is below 5.5

Bacteria present in the mouth produce acids by degradation of sugar and food particles remaining in the mouth after eating

The best way to prevent this is to clean the mouth after eating food

Some Naturally-Occurring Acids: Acetic acid from vinegar, citric acid from orange, and lemon, tartaric acid from tamarind; oxalic acid from tomato, lactic acid from sour milk (curd), aceticc acid from and sting and nettle sting

Tooth enamel is made up of calcium phosphate is the hardest substance in the body

It does not dissolve in water but is corroded when the pH in the mouth is below 5.5

Bacteria present in the mouth produce acids by degradation of sugar and food particles remaining in the mouth after eating

The best way to prevent this is to clean the mouth after eating food

Introduction: while eating some curry falls on Rishi's shirt He rushes to clean the stain of turmeric with soap but to his surprise the stain becomes orange-red after washing with soap

How the stain changed the color on applying soap? Let us find out in this lesson what caused this color change?

Objectives: At the end of this lesson you will be able to explain indicators and its kinds, describe the function of indicators; define neutralization.

Students, how can you find that a fruit is acidic or basic?

You can easily test the acidic or basic nature of a substance by making a simple indicator solution at home

IYou will need beaker, gas stove, petals of China Rose, a clean glass bottle, three small glasses, lemon juice soap solution and distilled water

How the stain changed the color on applying soap? Let us find out in this lesson what caused this color change?

Objectives: At the end of this lesson you will be able to explain indicators and its kinds, describe the function of indicators; define neutralization.

Students, how can you find that a fruit is acidic or basic?

You can easily test the acidic or basic nature of a substance by making a simple indicator solution at home

IYou will need beaker, gas stove, petals of China Rose, a clean glass bottle, three small glasses, lemon juice soap solution and distilled water

Pour some distilled water in a beaker and heat it on the gas stove.

Objectives: At the end of this lesson you will be able to explain indicators and its kinds, describe the function of indicators; define neutralization.

Students, how can you find that a fruit is acidic or basic?

You can easily test the acidic or basic nature of a substance by making a simple indicator solution at home

IYou will need beaker, gas stove, petals of China Rose, a clean glass bottle, three small glasses, lemon juice soap solution and distilled water

Pour some distilled water in a beaker and heat it on the gas stove.

Heat till the water becomes warm; then to this warm water add petals of China rose

Students, how can you find that a fruit is acidic or basic?

You can easily test the acidic or basic nature of a substance by making a simple indicator solution at home

IYou will need beaker, gas stove, petals of China Rose, a clean glass bottle, three small glasses, lemon juice soap solution and distilled water

Pour some distilled water in a beaker and heat it on the gas stove.

Heat till the water becomes warm; then to this warm water add petals of China rose

Keep the mixture for some time till water becomes colored

You can easily test the acidic or basic nature of a substance by making a simple indicator solution at home

IYou will need beaker, gas stove, petals of China Rose, a clean glass bottle, three small glasses, lemon juice soap solution and distilled water

Pour some distilled water in a beaker and heat it on the gas stove.

Heat till the water becomes warm; then to this warm water add petals of China rose

Keep the mixture for some time till water becomes colored

Filter this purple red water in a bottle with a tea strainer

This purple red solution is your indicator

Pour some distilled water in a beaker and heat it on the gas stove.

Heat till the water becomes warm; then to this warm water add petals of China rose

Keep the mixture for some time till water becomes colored

Filter this purple red water in a bottle with a tea strainer

This purple red solution is your indicator

Then take small amount of this indicator in three small glasses

Heat till the water becomes warm; then to this warm water add petals of China rose

Keep the mixture for some time till water becomes colored

Filter this purple red water in a bottle with a tea strainer

This purple red solution is your indicator

Then take small amount of this indicator in three small glasses

Pour lemon juice in the first-glass; water in the second glass and soap solution in the third glass

Keep the mixture for some time till water becomes colored

Filter this purple red water in a bottle with a tea strainer

This purple red solution is your indicator

Then take small amount of this indicator in three small glasses

Pour lemon juice in the first-glass; water in the second glass and soap solution in the third glass

What do you see? As you can notice that in glass one color changes to dark pink

Filter this purple red water in a bottle with a tea strainer

This purple red solution is your indicator

Then take small amount of this indicator in three small glasses

Pour lemon juice in the first-glass; water in the second glass and soap solution in the third glass

What do you see? As you can notice that in glass one color changes to dark pink

Lemon juice is acidic in nature so there is a change in the color of the indicator

You can see that there is no color change in glass 2, why this is so?

Then take small amount of this indicator in three small glasses

Pour lemon juice in the first-glass; water in the second glass and soap solution in the third glass

What do you see? As you can notice that in glass one color changes to dark pink

Lemon juice is acidic in nature so there is a change in the color of the indicator

You can see that there is no color change in glass 2, why this is so?

This is because water is neutral in nature.

Pour lemon juice in the first-glass; water in the second glass and soap solution in the third glass

What do you see? As you can notice that in glass one color changes to dark pink

Lemon juice is acidic in nature so there is a change in the color of the indicator

You can see that there is no color change in glass 2, why this is so?

This is because water is neutral in nature.

The color in third glass changes to green.

What do you see? As you can notice that in glass one color changes to dark pink

Lemon juice is acidic in nature so there is a change in the color of the indicator

You can see that there is no color change in glass 2, why this is so?

This is because water is neutral in nature.

The color in third glass changes to green.

Thus we can conclude that the indicator solution obtained from China rose turns bright pink in the presence of an acid and green in the presence of a base

Lemon juice is acidic in nature so there is a change in the color of the indicator

You can see that there is no color change in glass 2, why this is so?

This is because water is neutral in nature.

The color in third glass changes to green.

Thus we can conclude that the indicator solution obtained from China rose turns bright pink in the presence of an acid and green in the presence of a base

We can put a drop of this indicator solution in the desired food item to know whether it is acidic or basic

What is the taste of water? is it sour or bitter?

This is because water is neutral in nature.

The color in third glass changes to green.

Thus we can conclude that the indicator solution obtained from China rose turns bright pink in the presence of an acid and green in the presence of a base

We can put a drop of this indicator solution in the desired food item to know whether it is acidic or basic

What is the taste of water? is it sour or bitter?

It is neither of the both as water is neither an acid nor a base

The color in third glass changes to green.

Thus we can conclude that the indicator solution obtained from China rose turns bright pink in the presence of an acid and green in the presence of a base

We can put a drop of this indicator solution in the desired food item to know whether it is acidic or basic

What is the taste of water? is it sour or bitter?

It is neither of the both as water is neither an acid nor a base

The substances that are neither acid nor a base are called neutral solution

Thus we can conclude that the indicator solution obtained from China rose turns bright pink in the presence of an acid and green in the presence of a base

We can put a drop of this indicator solution in the desired food item to know whether it is acidic or basic

What is the taste of water? is it sour or bitter?

It is neither of the both as water is neither an acid nor a base

The substances that are neither acid nor a base are called neutral solution

Litmus is a natural indicator. It is extracted from lichens. It has a mauve color

We can put a drop of this indicator solution in the desired food item to know whether it is acidic or basic

What is the taste of water? is it sour or bitter?

It is neither of the both as water is neither an acid nor a base

The substances that are neither acid nor a base are called neutral solution

Litmus is a natural indicator. It is extracted from lichens. It has a mauve color

In distilled water it is available in the form of a solution called litmus papers

You can test the nature of a solution by litmus paper

It is neither of the both as water is neither an acid nor a base

The substances that are neither acid nor a base are called neutral solution

Litmus is a natural indicator. It is extracted from lichens. It has a mauve color

In distilled water it is available in the form of a solution called litmus papers

You can test the nature of a solution by litmus paper

Dip a clean stirring rod into the baking powder solution and then touch the wet stirring rod to the red litmus paper red

The substances that are neither acid nor a base are called neutral solution

Litmus is a natural indicator. It is extracted from lichens. It has a mauve color

In distilled water it is available in the form of a solution called litmus papers

You can test the nature of a solution by litmus paper

Dip a clean stirring rod into the baking powder solution and then touch the wet stirring rod to the red litmus paper red

Litmus paper turns blue indicating that the baking powder solution is alkaline in nature

Litmus is a natural indicator. It is extracted from lichens. It has a mauve color

In distilled water it is available in the form of a solution called litmus papers

You can test the nature of a solution by litmus paper

Dip a clean stirring rod into the baking powder solution and then touch the wet stirring rod to the red litmus paper red

Litmus paper turns blue indicating that the baking powder solution is alkaline in nature

Again dip a clean stirrer into the vinegar solution

In distilled water it is available in the form of a solution called litmus papers

You can test the nature of a solution by litmus paper

Dip a clean stirring rod into the baking powder solution and then touch the wet stirring rod to the red litmus paper red

Litmus paper turns blue indicating that the baking powder solution is alkaline in nature

Again dip a clean stirrer into the vinegar solution

Put one drop on blue litmus paper

Blue litmus paper becomes red indicating vinegar is acidic in nature

Dip a clean stirring rod into the baking powder solution and then touch the wet stirring rod to the red litmus paper red

Litmus paper turns blue indicating that the baking powder solution is alkaline in nature

Again dip a clean stirrer into the vinegar solution

Put one drop on blue litmus paper

Blue litmus paper becomes red indicating vinegar is acidic in nature

Let us perform a simple experiment. Take some hydrochloric acid in the beaker then add some phenolphthalein into it

Litmus paper turns blue indicating that the baking powder solution is alkaline in nature

Again dip a clean stirrer into the vinegar solution

Put one drop on blue litmus paper

Blue litmus paper becomes red indicating vinegar is acidic in nature

Let us perform a simple experiment. Take some hydrochloric acid in the beaker then add some phenolphthalein into it

Now add sodium hydroxide drop-wise to this solution with continuous stirring

Again dip a clean stirrer into the vinegar solution

Put one drop on blue litmus paper

Blue litmus paper becomes red indicating vinegar is acidic in nature

Let us perform a simple experiment. Take some hydrochloric acid in the beaker then add some phenolphthalein into it

Now add sodium hydroxide drop-wise to this solution with continuous stirring

After some time, the pink color slowly appears in the solution.

Put one drop on blue litmus paper

Blue litmus paper becomes red indicating vinegar is acidic in nature

Let us perform a simple experiment. Take some hydrochloric acid in the beaker then add some phenolphthalein into it

Now add sodium hydroxide drop-wise to this solution with continuous stirring

After some time, the pink color slowly appears in the solution.

When we add more sodium hydroxide, the pink colour becomes a brighter on adding a drop of hydrochloric acid this solution again becomes colorless

So phenylene appears pink in alkaline solution, and colorless in acidic solution. It is colorless in neutral medium.

Let us perform a simple experiment. Take some hydrochloric acid in the beaker then add some phenolphthalein into it

Now add sodium hydroxide drop-wise to this solution with continuous stirring

After some time, the pink color slowly appears in the solution.

When we add more sodium hydroxide, the pink colour becomes a brighter on adding a drop of hydrochloric acid this solution again becomes colorless

So phenylene appears pink in alkaline solution, and colorless in acidic solution. It is colorless in neutral medium.

Fill in the blanks by selecting the suitable option

Now add sodium hydroxide drop-wise to this solution with continuous stirring

After some time, the pink color slowly appears in the solution.

When we add more sodium hydroxide, the pink colour becomes a brighter on adding a drop of hydrochloric acid this solution again becomes colorless

So phenylene appears pink in alkaline solution, and colorless in acidic solution. It is colorless in neutral medium.

Fill in the blanks by selecting the suitable option

Let us do an activity to understand neutralization reaction

After some time, the pink color slowly appears in the solution.

When we add more sodium hydroxide, the pink colour becomes a brighter on adding a drop of hydrochloric acid this solution again becomes colorless

So phenylene appears pink in alkaline solution, and colorless in acidic solution. It is colorless in neutral medium.

Fill in the blanks by selecting the suitable option

Let us do an activity to understand neutralization reaction

Materials needed are: a piece of chalk, vinegar and a test tube.

When we add more sodium hydroxide, the pink colour becomes a brighter on adding a drop of hydrochloric acid this solution again becomes colorless

So phenylene appears pink in alkaline solution, and colorless in acidic solution. It is colorless in neutral medium.

Fill in the blanks by selecting the suitable option

Let us do an activity to understand neutralization reaction

Materials needed are: a piece of chalk, vinegar and a test tube.

Drop some crushed chalk in the test tube.

Add vinegar to the test tube, watch what happens?

Fill in the blanks by selecting the suitable option

Let us do an activity to understand neutralization reaction

Materials needed are: a piece of chalk, vinegar and a test tube.

Drop some crushed chalk in the test tube.

Add vinegar to the test tube, watch what happens?

The chalk reacts with the vinegar.

Let us do an activity to understand neutralization reaction

Materials needed are: a piece of chalk, vinegar and a test tube.

Drop some crushed chalk in the test tube.

Add vinegar to the test tube, watch what happens?

The chalk reacts with the vinegar.

As the chalk reacts, the bubbles of carbon dioxide comes out

Materials needed are: a piece of chalk, vinegar and a test tube.

Drop some crushed chalk in the test tube.

Add vinegar to the test tube, watch what happens?

The chalk reacts with the vinegar.

As the chalk reacts, the bubbles of carbon dioxide comes out

A white solid is formed on the plate which is calcium acetate

Drop some crushed chalk in the test tube.

Add vinegar to the test tube, watch what happens?

The chalk reacts with the vinegar.

As the chalk reacts, the bubbles of carbon dioxide comes out

A white solid is formed on the plate which is calcium acetate

Chalk is calcium carbonate, vinegar is acetic acid in water

When they react carbon dioxide water and calcium acetate are formed

The chalk reacts with the vinegar.

As the chalk reacts, the bubbles of carbon dioxide comes out

A white solid is formed on the plate which is calcium acetate

Chalk is calcium carbonate, vinegar is acetic acid in water

When they react carbon dioxide water and calcium acetate are formed

Thus we can say that an acid reacts with a base to form salt

As the chalk reacts, the bubbles of carbon dioxide comes out

A white solid is formed on the plate which is calcium acetate

Chalk is calcium carbonate, vinegar is acetic acid in water

When they react carbon dioxide water and calcium acetate are formed

Thus we can say that an acid reacts with a base to form salt

Summary : Let us summarize what we have learnt

A white solid is formed on the plate which is calcium acetate

Chalk is calcium carbonate, vinegar is acetic acid in water

When they react carbon dioxide water and calcium acetate are formed

Thus we can say that an acid reacts with a base to form salt

Summary : Let us summarize what we have learnt

An indicator is defined as a substance which is used to test whether a substance is acidic or basic by means of a characteristic change in color.

Chalk is calcium carbonate, vinegar is acetic acid in water

When they react carbon dioxide water and calcium acetate are formed

Thus we can say that an acid reacts with a base to form salt

Summary : Let us summarize what we have learnt

An indicator is defined as a substance which is used to test whether a substance is acidic or basic by means of a characteristic change in color.

The solutions which do not change the color of an indicator are called neutral solutions.

They are neither acidic nor basic in nature

Thus we can say that an acid reacts with a base to form salt

Summary : Let us summarize what we have learnt

An indicator is defined as a substance which is used to test whether a substance is acidic or basic by means of a characteristic change in color.

The solutions which do not change the color of an indicator are called neutral solutions.

They are neither acidic nor basic in nature

The indicators that are found in nature are called natural indicators

Summary : Let us summarize what we have learnt

An indicator is defined as a substance which is used to test whether a substance is acidic or basic by means of a characteristic change in color.

The solutions which do not change the color of an indicator are called neutral solutions.

They are neither acidic nor basic in nature

The indicators that are found in nature are called natural indicators

Llitmus is an example of a natural indicator which is widely used as it's turned blue litmus red

An indicator is defined as a substance which is used to test whether a substance is acidic or basic by means of a characteristic change in color.

The solutions which do not change the color of an indicator are called neutral solutions.

They are neither acidic nor basic in nature

The indicators that are found in nature are called natural indicators

Llitmus is an example of a natural indicator which is widely used as it's turned blue litmus red

Whereas a basic solution turns red litmus blue

The solutions which do not change the color of an indicator are called neutral solutions.

They are neither acidic nor basic in nature

The indicators that are found in nature are called natural indicators

Llitmus is an example of a natural indicator which is widely used as it's turned blue litmus red

Whereas a basic solution turns red litmus blue

The reaction between an acid and a base is known as neutralization

They are neither acidic nor basic in nature

The indicators that are found in nature are called natural indicators

Llitmus is an example of a natural indicator which is widely used as it's turned blue litmus red

Whereas a basic solution turns red litmus blue

The reaction between an acid and a base is known as neutralization

They are neither acidic nor basic in nature

The indicators that are found in nature are called natural indicators

Llitmus is an example of a natural indicator which is widely used as it's turned blue litmus red

Whereas a basic solution turns red litmus blue

The reaction between an acid and a base is known as neutralization

They are neither acidic nor basic in nature

The indicators that are found in nature are called natural indicators

Llitmus is an example of a natural indicator which is widely used as it's turned blue litmus red

Whereas a basic solution turns red litmus blue

The reaction between an acid and a base is known as neutralization

They are neither acidic nor basic in nature

The indicators that are found in nature are called natural indicators

Llitmus is an example of a natural indicator which is widely used as it's turned blue litmus red

Whereas a basic solution turns red litmus blue

The reaction between an acid and a base is known as neutralization