The rate of evaporation increases with an increase of
Pressure
Temperature
Density
Volume
The amount of heat energy that is required to change 1kg of a solid into liquid at atmospheric pressure at its melting point is known as
Fusion point
Latent heat of fusion
Condensation
Evaporation
The quantity of matter present in an object is called its
weight
gram
mass
density
The temperature at which solid melts to become liquid at the atmospheric pressure is called its
Melting point
Boiling point
Freezing point
Sublimation temperature
In an experiment to find the melting point of ice the correct reading of thermometer is noted when
ice starts melting
whole of the ice melts
temperture starts increasing
temperature becomes constant
At room temperature (30°C) a student sets up an apparatus to determine the melting point of ice. He takes a beaker filled with ice and dips a mercury thermometer in it.The correct observation is:
mercury in the thermometer keeps on falling till reads 1°C, it remains constant thereafter.
temperature falls, reaches 0°C, then it reamins constant even after the whole ice has melted.
the temperature falls initially but begins to rise as soon as the ice starts melting.
temperature falls, reaches to 0°C and remains constant only as long as both ice and water are present in it.
In order to find the boiling point of water one of the precautions is that the bulb of the thermometer should not touch the sides of the beaker. This precaution is taken because:
sides of the beaker are at slightly higher temperature than 100°C.
sides of the beaker are at slightly lower temperature than 100°C.
the bulb of thermometer is likely to break.
none of the above.
A beaker contains 50g of ice and water mixture. The temperature of this mixture is :
less than 0°C
0°C
more than 0°C
4°C
A bottle of ammonia and a bottle of dry hydrogen chloride connected through a long tube are opened simultaneously at both ends, the white ammonium chloride ring first formed will be
at the centre of the tube
near the hydrogen chloride bottle
near the ammonia bottle
throughout the length of the tube
When we put some crystals of potassium permanganate in a beaker containing water, we observe that after sometime whole water has turned pink. This is due to
boling
melting of potassium permanganate crystals
sublimation of crystals
diffusion
