Chemistry

Matter

noreply@blogger.com (Rupesh lunar singh) — Mon, 4 May 2020 09:56:00 +0530

[Study material]Matter in our surroundings

There are a large number of things around us which we see and feel. For example, you can see this post in front of you. This post occupies some space. The space occupied by the ball is called its volume. If you pick up the ball, you can also feel its weight. So, you conclude that the book has some mass. You cannot see the air around you, yet if you feel a balloon with year and then weight it carefully, you will find that it not only does Air occupy space ( bonded by the balloon), but it also has mass. Things like ball and air are example of matter. Other example of matter are wood, cloth, paper, ice, steel, water, oil, etc. further, that matter offers resistance in borne out by the fact that you cannot display an object from one place to another without applying some forces. You have to apply force to pick up a stone from the ground. On the contrary, light, heat, sound, electricity, etc., are not matter because they do not have any mass and they do not occupy space.

Thus, matter can be defined as follows.

Anything that occupies space, has mass and offers resistance is called matter.

What is substance.

A substance is a kind of matter that can’t be separated into other kinds of matter by any physical process. For example, sugar dissolved in water be separated from water by simply evaporating the water. Here, sugar is a substance which can’t be broken into its component by any physical process. Similarly, sodium chloride, lime (calcium oxide), etc., are all substances.

Physical nature of matter.

1. Matter is made up particles

The ancient philosophers held the view that matter is continuous, like a block of wood. But this is not true. Actually, matter is made up of discrete particles. This can be easily e verified by performing the following activity.

Take care a beaker. Fill half of it with water. Mark the level of water in the beaker. Address of sugar to the water and dissolved it with the help of a glass rod. You will see that the sugar has disappeared, but there is no change in the level of water. Can you say a where has the sugar gone? This can be explained by assuming that matter is not continuous,rather it is made up of particles. Sugar contains a large number of separate particles. These particles when dissolved in water occupies the space between the particles of water. That is why the water level in the beaker did not rise. Had sugar been continuous, like a block of wood, the water level in the beaker would have risen.

2. The particles of matter are too small to be imagined

This can be explained by performing the following activity.

Step 1 take some crystals of blue vitriol (copper sulphate) and dissolve them in 100 ml of water. The solution will go blue.

Step 2 take about 10 ml of the blue solution prepared in step 1. Add it to another hundred ml of face water.

Step 3 take about 10 ml of the solution prepared in step 2. Add it to another 100 ml of fresh water.

In this way, repeat the exercise 5 to 8 times. You will find that the last solution is a steel blue though the intensity of the colour has gradually decreased.

This indicates that a few crystals of copper sulphate are able to colour and enormously large volume of water. This also shows that a small crystal of copper sulphate contains millions of small particles.

3. The particles of some matter are in constant motion

The following activity shows that the particle of some matter are always moving.

Put an incense stick (agarbati) in a corner of your room. You can’t get it smell from a distance. For that, you have to move closer to it. Now, light the stick with a matchstick. You can now get its smell even if you are sitting at a distance. Why? The particles of perfume present in the incense stick freely mixed with the particles of air and have a speed across the room. Is the particles where not movie, the smell of the incense stick would never have recharged you.

4. The particle of matter attract each other

The particles of matter are held Together by a force acting between them. This force is called intermolecular force of attraction.

The strength of the intermolecular force of attraction differs from matter to matter.

Take an iron nail, a stick of Chalk and a small pieces of brick. Strike each of them separately with a hammer. You will observe that the stick of Chalk gets broken into pieces easily, the piece of brick brakes but not so easily, but it is most difficult to break the iron nail. What do these observations say? It is clear that the particles of iron nail are held Together by the strongest force followed by the pieces of brick, whereas the particle of Chalk have the weakest force of attraction.

5. The particle of matter have empty space between them

During the dissolution of sugar in water the particle of sugar occupy the important space between the particles of water. The Imperial space is called intermolecular space or intermolecular volume.

an iron almirah DJ solid at room temperature give two reason to justify

noreply@blogger.com (Rupesh lunar singh) — Tue, 28 Apr 2020 07:06:00 +0530

an iron almirah is a solid because it has definite shape. You cannot flow it means it is solid.

water at room temperature is a liquid give two reason to justify

noreply@blogger.com (Rupesh lunar singh) — Tue, 28 Apr 2020 07:03:00 +0530

Water is liquid at normal temperature because it has no definite shape. It acquires the shape of the same container in which it is kept. Secondly it can flow easily. It means it is liquid not solid

we can get the smell of perfume sitting several metre away give reason

noreply@blogger.com (Rupesh lunar singh) — Tue, 28 Apr 2020 07:01:00 +0530

Particles of scent mix with the particle of air automatically and spread everywhere. Due to this scattering of particles a man sitting at some distance can a smell the scent

Naphthalene balls disappear with time without leaving any solid give reason

noreply@blogger.com (Rupesh lunar singh) — Tue, 28 Apr 2020 07:00:00 +0530

Naphthalene balls disappear without leaving any Residue because they are sublimated. In other words they are converted into gaseous state directly

why is ice at 273 K more effective in cooling than water at the same temperature

noreply@blogger.com (Rupesh lunar singh) — Tue, 28 Apr 2020 06:57:00 +0530

The energy of ice particles at 273 k A remains lower to the particles of water. As a result ice can absorb more energy from atmosphere this is the reason why being on equal temperature ice can cool more than water

what produce more Severe Burns boiling water or stream

noreply@blogger.com (Rupesh lunar singh) — Mon, 27 Apr 2020 05:42:00 +0530

At 373 K the energy of particles of vapour remains greater than the energy of particle of water at equal temperature. This happens due to the fact that particles of vapour absorb excess energy in form of latent heat of vaporization Hence when vapour comes in contact of a screen it is releasing energy more than the water boiling at the same temperature as a result steam produce more Severe burns than boiling water

why should we wear cotton clothes in summer

noreply@blogger.com (Rupesh lunar singh) — Mon, 27 Apr 2020 05:37:00 +0530

cotton clothes are good absorbers of water it helps in absorption of sweat and leaves it exposure for simple vaporization the sweat turns into vapour very fast the latent heat of vaporization is taken from the body and we feel good

what type of clothes should we wear in summer

noreply@blogger.com (Rupesh lunar singh) — Sun, 26 Apr 2020 05:56:00 +0530

In summer we should wear white or light colour cloth white aur light coloured clothes are good reflector of light due to this we feel cool

why are we able to sip hot tea or milk faster from a saucer rather than a cup

noreply@blogger.com (Rupesh lunar singh) — Sun, 26 Apr 2020 05:53:00 +0530

The area of surface of Milk or tea in a cup is less. It cause slow evaporation due to which it becomes old slowly so it takes time in sipping when the tea is kept in a plate the area of the surface of milk or tea increases it it leads to fast evaporation. Thus, it takes list time in cooling show the milk or tea can be sipped quickly

why does our Palm feel cold when we put some Acetone or petrol or perfume on it

noreply@blogger.com (Rupesh lunar singh) — Sun, 26 Apr 2020 05:49:00 +0530

Acetone/ petrol or scent are volatile substance when these are put on plan their vaporization becomes faster due to the plum for this the substance take energy from the plan due to which it become cold

how does the water kept in an pitcher ( Earthen pot, Matka) become cool during summer

noreply@blogger.com (Rupesh lunar singh) — Sun, 26 Apr 2020 05:46:00 +0530

During summer there is less water vapour in atmosphere teachers have a small pores though which water keeps up coming out slowly. This happens around the pitches it leads to cooling a water of the pitcher.

why does a desert cooler cool better on a hot dry day

noreply@blogger.com (Rupesh lunar singh) — Sun, 26 Apr 2020 05:43:00 +0530

Hot dry days have less water vapour in atmosphere they encourage to increase the rate of evaporation. Cooler runs its water it takes energy from atmosphere for its vaporization and evaporated fast. Thus cooler cools better on a hot dry day

why do liquids have fixed volume

noreply@blogger.com (Rupesh lunar singh) — Sun, 26 Apr 2020 05:40:00 +0530

A liquid has fixed volume because the space among its molecule at a given temperature is fixed

why do solid have fixed shape

noreply@blogger.com (Rupesh lunar singh) — Sun, 26 Apr 2020 05:40:00 +0530

Particles of solid have greater force of attraction the remains close to each other in they have fixed shapes.

why do gases not have a fixed shape nor a fixed value

noreply@blogger.com (Rupesh lunar singh) — Sun, 26 Apr 2020 05:39:00 +0530

Gases do not have fixed shape. This is because the position of their molecules is not fixed gases do not have fixed volume because the area of a space between their molecules is not fixed

liquid generally have lower density as compared to solids but you must have observed that ice floats on water find out why

noreply@blogger.com (Rupesh lunar singh) — Sun, 26 Apr 2020 05:37:00 +0530

FB status of AI floats on water because its volume is Greater if can replace water having more weight this is the reason why a fishes of ice floats on water the volume of ice is greater than the water of which it is made

when we can easily move our hand in air but to do the same through a solid block of wood we need to be a Karate expert give reason

noreply@blogger.com (Rupesh lunar singh) — Sun, 26 Apr 2020 05:35:00 +0530

we can move hand in we can move hand in air is leave because its molecule can easily the displays it is so because they have very less force between them. Particles of would have very less space left among them in the force of attraction is Greater there so for moving our hand though a solid block of wood far greater force is needed which is possible only for an expert of karate

a wooden table should be called a solid give reason

noreply@blogger.com (Rupesh lunar singh) — Sun, 26 Apr 2020 05:33:00 +0530

Particles of wood are connected with great forces it is called as solid table is made of wood is it is called solid

a gas fills completely The vessel in which it is kept give reason

noreply@blogger.com (Rupesh lunar singh) — Sun, 26 Apr 2020 05:33:00 +0530

Particles of a gas remain for a part other they have a property of flour due to this reason a gas spared in the entire container

what are the characteristics of the particles of matter

noreply@blogger.com (Rupesh lunar singh) — Sun, 26 Apr 2020 05:31:00 +0530

Characteristics of particle of matter -

Particles of matter contain flank spaces.
Particle of matter remain in continuous motion.
Particle of matter attract each other.

A diver is able to cut through water in a swimming pool. which property of matter does this observation show

noreply@blogger.com (Rupesh lunar singh) — Sun, 26 Apr 2020 05:29:00 +0530

swimming pool has water which is swimming pool has water which is in liquid state. Proceeding through water indicate what the force applied between water particle is lesser. Due to this water molecule get separate easily

give reason for the following observation - the smell of hot sizzling food reaches you several metres away but to get the mail from cold food you have to go close

noreply@blogger.com (Rupesh lunar singh) — Sun, 26 Apr 2020 05:27:00 +0530

Particles of a substance remain motile continually. When temperature rise the motion of particles become faster does mail from food reaches to us though diffusion. The temperature of hot food we mean by the diffusion rate of hot food remains as compared to cold food so it's made reach to us from several metres away

name the isotope used in atomic furnace as fuel

noreply@blogger.com (Rupesh lunar singh) — Sat, 18 Apr 2020 12:32:00 +0530

Uranium

name the isotope which is used to cure cancer

noreply@blogger.com (Rupesh lunar singh) — Sat, 18 Apr 2020 12:31:00 +0530

Isotope of Cobalt