chapter 1 Flashcards
what is matter?
anything that has mass and occupies space is known as matter
what did philosophers classify matter as ?
in olden days philosophers classified matter as panchatatva i.e. air, fire, water, sky and earth
how many particles of matter are present in just one crystal?
millions if not billions
are matter of particles are constantly in motion ?
yes
what is intermixing of 2 different type of matter own their own known as?
diffusion
what energy do particles of matter posses?
kinetic energy
what keeps particle of matter attracted?
force
what are the three features of solid
- definite volume
- distinct boundaries
- fixed volumes
do liquids have fixed shape?
no
do liquids have fixed volume?
yes
can solid, liquid and gas diffuse in liquids
yes
whose rate of diffusion is high
liquid or solid
liquid
which of the following are highly compressible
gases
liquid
solid
arrange in ascending odder?
solid
liquid
gas
what are three states of matter?
solid
liquid
gas
what happens on increasing of temperature in solids ?
On increasing the temperature of solids. the kinetic energy of the particles increases. Due to the increase in kinetic energy, the particles start vibrating with greater speed. The energy supplied by heat overcomes the forces of attraction between the particles. The particles leave their fixed positions and start moving more freely.
what’s the temperature ice melts at k?
The melting point of ice is 273.15 K
When a solid melts, its temperature remains the same, so where does the heat energy go?
the heat gets used up in changing the state by overcoming force of attraction between the particles
what is latent heat?
when heat gets used up in changing the state by overcoming the forces of attraction between the particles.
what is boiling point?
The temperature at which a liquid starts boiling at the atmospheric pressure is known as its boiling point
what’s the boiling point of water?
373k
or
100 degree Celsius
what is sublimation ?
A change of state directly from solid to gas without changing into liquid state is called sublimation
what is deposition ?
the direct change of gas to solid without changing into liquid is called deposition.
what can liquefy gas?
Applying pressure and reducing temperature can liquefy gases
explain the conversion of carbon dioxide?
Solid CO₂ gets converted directly to gaseous state on decrease of pressure to atmosphere without coming into liquid state. This is the reason that solid carbon dioxide is also known as dry ice.
what can determine the state of a matter?
pressure and temperature determine the state of a substance, whether it will be solid, liquid or gas.
define evaporation?
the process liquid turning into solid below its boiling point is known as evaporation
the rate of evaporation is based on:
explain with an example
We know that evaporation is a surface phenomenon. If the surface area is Increased, the rate of evaporation increases. For example, while putting clothes for drying up we spread them out. an increase of temperature:
.With the increase of temperature, more number of particles get enough kinetic energy to go into the vapour state. a decrease in humidity:
Humidity is the amount of water vapour present in air. The air around us cannot hold more than a definite amount of water vapour at a given temperature. If the amount of water in air is already high, the rate of evaporation decreases. an increase in wind speed:
It is a common observation that clothes dry faster on a windy day. With the increase in wind speed, the particles of water vapour move away with the wind. decreasing the amount of water vapour in the surrounding.
define melting
Melting: The process in which solid changes into liquid is called melting. It is also called fusion.
define freezing
Freezing: The process of converting liquid into solid is called freezing. e.g. convert water into ice in fridge in ice
define boiling
Boiling: The process of converting liquid into vapour completely is called boiling. It is bulk phenomenon, i.e. particles from inside the liquid gain enough energy to change into vapour state. It takes place only at boiling point.
define condensation
Condensation The process of converting gas or vapour into liquid is called condensation, e.g. water vapours get condensed on the surface of glass containing chilled water.
what are the factors affecting diffusion
- Density: The rate of diffusion depends upon density of liquid. Higher the density, lesser will be the rate of diffusion.
- Temperature: The rate of diffusion depends upon temperature, i.e. the rate of diffusion increases with an increase in temperature which can be shown experimentally.
- Physical State: Solids can diffuse into liquids slowly whereas liquids can diffuse into liquids faster and gases can also diffuse into liquids.
The smell of hot sizzling food reaches you several metres away, but to get the smell from cold food you have to go closer.
The smell of vapours coming out from hot sizzling food mix with air and reach us faster even at several meters away because rate of diffusion increases with increase in temperature. The smell of cold food cannot reach us as diffusion is slow at low temperature.
