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.
what are solid crystal lattice structures determined by?
x ray crystallography
Lattice energy of NaCl is
-787 kJ/mol
Based on the type of bonds crystalline solids may be divided into how many types?
Four types:
1) Ionic solids
2) Covalent solids
3) Metallic solids
4) Molecular solids
Which solids is generally the hardest one?
covalent solids
On the basis of regular arrangements of the 2 constituents, the solids can be divided into how many types?
Two Types:
1. Crystalline solids
2. Amorphous solids
lattice energy depends on
LE is directly proportional to charge but inversely to size
The structure of sodium chloride is
Face centered cube
Transition temperature of Tin (Sn) from gray (cubic) to white (tetragonal) is
13.2 C
A malleable solid is one which can be
Converted into thin sheets
The transition temperature of KNO₃ rhombohedral to orthorhombic
128.5 C
what is meant by transition temperature
The temperature at which two crystalline forms of the same substance can co-exist in equilibrium with each other.
Coordination number of face centered cubic structure is
6
When 10% urea is present in NaCl solution then which crystal becomes
needle like 1-d
The viscosity of an ideal solids is
infinite
In orthorhombic crystal, the unit cell dimensions are
a≠b≠c α=β=γ=90°
The unit cell dimensions of triclinic crystal is
a≠b≠c α≠β≠γ≠90°
Liquid crystals are
Always anisotropic
A crystalline solid maybe isotropic or anisotropic and liquid crystals are always anisotropic because liquid crystal show variations in their coefficient of thermal expansion
Crystal lattice of substance can be categorized into
The 14 Bravais lattices are grouped into seven lattice systems: triclinic, monoclinic, orthorhombic, tetragonal, rhombohedral, hexagonal, and cubic.
SI unit of surface tension is:
Nm-1
Factors on which vapors pressure depends
(a) size of the molecules, (b) temperature, (c) inter molecular forces
In order to mention the boiling point of water at 110°C, the external pressure should be
Between 760 torr and 1200 torr
what causes lower vapor pressure
intermolecular forces such as hydrogen bonding
and
low temperature
When water freezes at 0°C, its density decreases due to
Empty spaces present in the structure of ice
when water freezes it occupies 9% more space
The highest temperature at which a substance can exist as a liquid is called?
critical temperature
Kerosene is liquid at room temperature due to
Molecular size
Greater the size of molecule, greater the polarizability, greater the forces of attractions.
what affects the rate of evaporation
Evaporation is directly proportional to the temperature and the surface area while inversely proportional to the strength of molecular forces
Correct order of boiling points
H2O > HF > NH3 > HCl
The boiling point of higher alkanes are greater than those of lower alkanes due to the reason that
The polarizability of higher alkanes are greater
As the sizes of the molecules increases the distortion also increases. This increase distortion of electronic cloud creates stronger London dispersion forces and hence the values of thermodynamic parameters increase.
what are the units of viscosity
cgs : poise
SI : Pa s or Ns m2-
the rms speed at NTP of a gas can be calculated from the expression
sqaure root (3P/d)
(3PV/M)
(3RT/M)
a liquid crystalline state exists between 2 temps, melting temp and —— temp
clearing
Quartz (SO2) is a —– crystal
covalent
liquid crystals are anisotropic fluids whose properties are an intermediate bw
crystals and isotropic liquids
liquid that forms convex meniscus in glass tube
mercury
london dispersion forces are strongest in (halogens)
Iodine
vapor pressure when a liquid boils is
the same for every liquid as it equals to external pressure
correct vanderwaals equation
(p + n^2 x a / v^2) x V-nb = nRT
formula for finding new volume using temp change
Vf = Vi + (Vi x T/273)
for temp decrease subtract, for increase add
