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An important facility for 9th class students preparing for short questions chemistry 9th class chapter 5 of BISE. Get hundreds of questions to prepare and get better marks in 9th chemistry
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Our database contains a total of 0 questions for chemistry Short Questions. You’ll prepare using this huge databank.

Question: 1
Define the term allotropy.
Answer: 1
The existence of an element in more than one form in same physical state is called allotropy.
Question: 2
Define Pascal.
Answer: 2
When one Newton force is acting on unit area called 1 Pascal. One Pascal (Pa) = 1 Nm-2
Question: 3
Does Kelvin scale show negative temperrature?
Answer: 3
No, Kelving scale does not show a negative temperature.
Question: 4
What is diffusion? Explain with an example?
Answer: 4
"Diffusion is defined as spontaneous mixing up of molecules by random motion and collisions to form a homogenous mixture". Example: H2 diffuses four times faster than O2 gas.
Question: 5
State Boyle law .
Answer: 5
"The volume of a given mass of a gas is inversely proportional to its pressure provided the temperature remains constant.
Question: 6
Whether the density of a gas decreases on cooling?
Answer: 6
the density of a gas increase by cooling because their volume decreases.
Question: 7
What do mean by evaporation and how it is affected by surface area?
Answer: 7
"The process of changing of a liquid into a gas phase is called evaporation. Surface Area: Evaporation is a surface phenomenon. Greater is surface area, greater is evaporation and vice versa. For example, sometimes a saucer is used if tea is to cooled quickly. this is because evaporation from larger surface area if source is more than that from the small surface area of a tea cup
Question: 8
Why does evaporation cause coaling?
Answer: 8
When the high kinetic energy molecules vaporize the temperature of remaining molecules falls down. to compensate this deficiency of energy, the molecules of liquid absorb energy from the surrounding. As a result the temperatureof surrounding decreases and we feel cooling.
Question: 9
Which form of Sulphur exists at room temperature?
Answer: 9
Rhombic sulphur exists at room temperature.
Question: 10
Define Vapour pressure?
Answer: 10
"The pressure exerted by the vapour of a liquid at equilibrium with the liquid a particular temperature is called vapour pressure of liquid."
Question: 11
Define Standard atmospheric pressure. What are its units? How it is relate to Pascal?
Answer: 11
"It is defined as the pressure exerted by a mercury column of 760 mm height at sea level". 1 atm 760 mm of Hf 760 torr 101325 Nm-2 101325 Pa
Question: 12
In Which form sulphur exists at 100 oC
Answer: 12
Sulphur exists in monoclinic form at 100 oc because at room temperature sulphur exists in rhombic form. The transition temperature of sulphur is 96 oc at which rhombic sulphur converted into monoclinic form.
Question: 13
Is the Boyle's law applicable to liquids?
Answer: 13
No, the Boyle's law is only applicable to gases.
Question: 14
What do you mean by dynamic equilibrium?
Answer: 14
Equilibrium is a state when rate of vaporization and rate of condensation is equal to each other but in opposite direction.
Question: 15
Define crystallinesolid?
Answer: 15
Solids in which particlesare arranged in a definite three dimensional pattern.
egdiamonds, sodium chloride, etc
Question: 16
Why volume of a gas decreases with increase of pressure?
Answer: 16
The volume of a given mass of a gas is inversely proportional to the pressure if the temperature is kept constant therefore while decreasing the volume of gas pressure will increase.
Question: 17
What is absolute temperature?
Answer: 17
It is the temperatureat which an ideal gas would have zero volume
Question: 18
What do you mean by condensation?
Answer: 18
"The process of conversion of vapours into liqid state is called condensation."
Question: 19
Explain the law of flow of heat?
Answer: 19
In winter atmospheric temperature falls lower than of our body temperature .According to Principle of heat flow, heat flows out from our body and we feel cold. To control this outward flow of heat. We wear black and warm clothes. To maintain body temperature we use dry fruits. tea, coffee and meats, etc.
Question: 20
State Charle's law. Also write its mathematicalpresentation?
Answer: 20
The volume of a givenmass of a gas is directly proportional to the absolute temperature if the presure is is kept constant.
Its mathematicalform is v=kt
Question: 21
Define pressure? Write its SI unit?
Answer: 21
The force exerted per unit surface area is called pressure Its SI unit is Nm-2
Question: 22
On which factor vapor pressure of any liquid depends?
Answer: 22
It depends upon1- Nature of liquid2- size of molecule temperature
Question: 23
Define vapor pressure?
Answer: 23
The pressure exerted by the vapors of a liquid at equilibrium with the liquid at a particular temperature.
Question: 24
Molecular formula of Sulphur molecule.
Answer: 24
The molecular formula of sulphur molecule is S8
Question: 25
Why is boiling point of water higher than of alcohol?
Answer: 25
Because water is polar molecule having strong intermolecular molecular forces while alcohol is a nonpolar compound having weak intermolecular forces. Therefore boiling point of water is higher than of alcohol
Question: 26
Define amorphous solid?
Answer: 26
Amorphous solid mans shapeless. Solids in which the particles are not regularly arranged .
Eg: Plastic, rubber etc
Question: 27
Why is vapour pressure higher at high temperature.
Answer: 27
All high temperature, vapour pressure is higher than at low temperature. At elevated temperature. The Kinetic energy of the molecules increases enough to enable them to vaporize and exert pressure.
Question: 28
Describe meltingpointof a solid?
Answer: 28
Melting point of solid is the temperature at which solid when heated melts and coexist in dynamic equilibriumwith liquid.
Question: 29
Which variables are kept constant in Charles law?
Answer: 29
Pressure is kept constant in Charles law.
Question: 30
Why boiling point of water is higher than alcohol?
Answer: 30
The boiling point of water is higher then alcohol because water has stronger intermolecular forces than alcohol
Question: 31
Define standard atmospheric pressure?
Answer: 31
It is the pressure exerted by the atmosphere at the sea level. It is defined as the pressure exerted by a mercury column of 760mm height at sea level.
Question: 32
What do you mean by pascal? How many pascal are equal to 1 atom?
Answer: 32
The SI unit of force is Newton and that of area is m2. Hence pressure has SI unit of Nm-2. It is also called Pascal.
1 atom = 1.1325 pa
Question: 33
Define boiling and freezing point?
Answer: 33
Boiling point:
The temperature at which the vaporpressure of a liquid becomes equal to the atmospheric pressure.
Question: 34
What do you mean by density?
Answer: 34
Density means how much mass a material has for a given volume
Question: 35
Write two liquid and gas differences?
Answer: 35
Liquid :
1- No fixed shape, but has volume
2- Cannot be stored without container
Question: 36
What is the relationship between evaporation and point of boiling of a liquid?
Answer: 36
A liquid having higher point of boiling will have slow evaporation due to stronger inter moleculeforces. A liquid having low boiling point will havefaster evaporation.