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 the determination of boiling point of water, it is advised to put the bulb of the thermometer in the steam rather than in water, it is to :
reduce the error due to atmospheric pressure.
make sure that boiling point obtained is accurate even when water sample contains non - volatile impurities dissolved.
reduce the error due to expansion of glass because of heat.
obtain the boiling point in a shorter time.
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.
Two students Arpit and Rakshita are asked to arrange the apparatus to determine the boiling point of water. They arranged the apparatus as shown below by figures A and B respectively :
The digram in which the apparatus is correctly arranged is :
A only
B only
both A and B
neither A nor B
While determining the boiling point of water, we should always use distilled water because :
impurities may break the thermometer.
impurities increase the boiling point of water.
impurities decrease the boiling point of water
impurities may stick to the thermometer making it difficult to read the temperature.
The quantity of matter present in an object is called its
weight
gram
mass
density
Matter that have a definite shape,distinct boundaries and fixed volumes are
Solids
Liquids
Gases
Kerosene
A thermometer has 20 equal divisions between 90°C and 100°C marks. A student while determining the boiling point of water finds that the mercury thread becomes stationary at the 19th mark above 90°C. He should record the boiling point of water as :
90.19°C
99.5°C
109°C
119°C
Physical state of water at 25°C, 0°C and 100°C respectively are :
liquid, solid, gas
solid, liquid, gas
liquid, gas, solid
gas, solid, liquid
LPG stands for
Low petroleum gas
Liquified petroleum gas
Low Pressure gas
Large pressure gas
