Answer : Option AExplaination / Solution:
Three phases of matter are :
1. Solid - firm and stable in shape; not liquid or fluid, strongest intermolecular forces.
2. Liquid - A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. Intermediate molecular forces.
3. Gas -Takes the volume of the container, weakest intermolecular forces.
Q3.dipole-dipole forces act between molecules that have
Answer : Option BExplaination / Solution:
dipole dipole forces act between molecules that have a permanent electrical dipole moment,the partial charge of one molecule get attracted to the opposite charge of other molecule
Q4.Which of the following statements about Hydrogen bond incorrect?
Answer : Option CExplaination / Solution:
Hydrogen atom covalently bonded to highly electronegative atom such as N,O experience electrostatic field of another highly electronegative atom due to which a partial positive charge is developed on H atom.
Q5.The intermolecular force primarily responsible for the condensed states of nonpolar substances is the
Answer : Option AExplaination / Solution:
The intermolecular force primarily responsible for the condensed states of nonpolar substances is the dispersion force (or London force).
Q6.The average Kinetic energy and Thermal energy are proportional to the
Answer : Option CExplaination / Solution:
The average KE and Thermal energy are proportional to absolute Temperature.
The kinetic energy is the amount of motion in the atoms and molecules of a substance. The moleculess of the gas gain energy as the temperature increases as there is more motion of the molecules. As the temperature decreases the motion lessens until at absolute zero all motion (kinetic energy) stops.
Answer : Option DExplaination / Solution:
Three states of matter are the result of balance between intermolecular forces and the thermal energy of the molecules. These two factors differentiate them from each other. For understanding, The strongest intermolecular forces are in solid then in liquid and weakest in gases.
Q8.Gases have much lower density than the solids and liquids because ?
Answer : Option DExplaination / Solution:
In gases, molecules are far apart from each other, thermal energy which is a measure of freeness of motion is thus very high resulting in a very large volume for the same mass(compared to solid and liquid). Hence there density is lowest.
Q9.At constant temperature, the pressure of a fixed amount (i.e., number of moles n) of gas is?
Answer : Option AExplaination / Solution:
From ideal gas equation PV=nRT,
keeping n and T fixed,
P α 1/V. (Boyles Law)
Here, T = Temperature
P = Pressure
α. = sign of Proportionality
V = Volume
n= number of moles of gas
R= Universal gas constant