states of matter Flashcards
1 atm = — torr
760 torr or mmHg
1 atm = —- Pa or pounds
101.325 kPa
14.7 pounds per inch
temperature at which molecular motion ceases and volume of gas is said to be 0 is called
absolute zero
0K = -273.15 C = -469 F
one torr is equal to
1 mm Hg
1 dm3 of a compound at STP contains — no. of molecules
2.68 x 1022
Avogadro no/ 22
Which of the following is the mathematical form of Avogadro’s law?
V = kn
The value of compressibility factor for an ideal gas is:
unity
Which of the following gas cannot liquefied by Linde’s method
The critical temperature of H2 is so low (-238˚C), that it cannot be achieved by Linde’s method. H2 and He can be liquefied by Claud’s method
CO2 and SO2 are both triatomic molecules but heat of vaporization of SO2 is greater than CO2. This is due to a:
Stronger the intermolecular forces greater will be the heat of vaporization and vice versa. SO2 is a polar gas, so strong attractive forces are present between molecules.
Equal volumes of all the ideal gases at the same temperature and pressure contain equal number of molecules. This is in accordance to:
Avogadro’s law
Charles’s law is only satisfied if temperature is taken on:
kelvin scale
The value of Vander Waal’s constant ‘a’ for gases O2, N2, NH3 and CH4 are 1.360, 1.390, 4.179 and 2.253 l2 atm moles-2 respectively. The gas which can most easily be liquefied is?
NH3
Van der Waal’s constant ‘a’ is an indirect measure of inter-molecular attractive forces. Ammonia contains strong inter-molecular forces of attraction. Inter-molecular hydrogen bonding is absent in other gases.
Hence, the value of van der Waal’s constant ‘a’ is larger for ammonia than compared to other gases.
Hence, ammonia can be most easily liquefied.
Which of the following is the mathematical form of Avogadro’s law?
V = kn
The value of compressibility factor for an ideal gas is:
unity
Which of the following gas cannot liquefied by Linde’s method
The critical temperature of H2 is so low (-238˚C), that it cannot be achieved by Linde’s method. H2 and He can be liquefied by Claud’s method
CO2 and SO2 are both triatomic molecules but heat of vaporization of SO2 is greater than CO2. This is due to a:
Stronger the intermolecular forces greater will be the heat of vaporization and vice versa. SO2 is a polar gas, so strong attractive forces are present between molecules.
Equal volumes of all the ideal gases at the same temperature and pressure contain equal number of molecules. This is in accordance to:
Avogadro’s law
Charles’s law is only satisfied if temperature is taken on:
kelvin scale
The value of Vander Waal’s constant ‘a’ for gases O2, N2, NH3 and CH4 are 1.360, 1.390, 4.179 and 2.253 l2 atm moles-2 respectively. The gas which can most easily be liquefied is?
NH3
Van der Waal’s constant ‘a’ is an indirect measure of inter-molecular attractive forces. Ammonia contains strong inter-molecular forces of attraction. Inter-molecular hydrogen bonding is absent in other gases.
Hence, the value of van der Waal’s constant ‘a’ is larger for ammonia than compared to other gases.
Hence, ammonia can be most easily liquefied.
Rate of diffusion of hydrogen is 8 times that of a gas X2. The molecular weight of X2 is?
128
Among the following gases which one has the lowest root mean square velocity at 25°C?
A. SO2
B. N2
C. O2
D. Cl2
Chlorine gas has the lowest root mean square speed at 25°C as it has highest molar mass (71 g/mol)
RMS speed is inversely proportional to the square root of molar mass.
Higher is the molar mass of the substance, lower is the root mean square velocity of it.
In a closed vessel, a gas is heated from 300K to 600K. The kinetic energy becomes/remains
According to KMT of gases:
“The average kinetic energy of the gas molecules varies directly as the absolute temperature of the gas “When temperature increases from 300K to 600k (double), the kinetic energy also becomes double.
Units of van der Waals constant “a” is
SI : atm dm6/mol2
common : Nm4/mol2
Crystallites are present in
amorphous solids
crystallite, any of a type of microscopic body occurring in such glassy igneous rocks as obsidian and pitchstone. Crystallites are regarded as incipient or embryonic crystals, though they often have no recognizable crystallographic form and are too small to polarize light.
