Which is lighter than dry air?
1. Moist air
2. SO2
3. Cl2
4. O2
Joule-Thomson coefficient ()H for an ideal gas is:
1. zero
2. +ve
3. -ve
4. none of these
The unit of van der Waals' constant 'b' is :
1. cm3 mol-1
2. litre mol-1
3. m3 mol-1
4. All of these
The beans are cooked in pressure cooker, because -
1. Boiling point increases with increasing pressure
2. Boiling point decreases with increasing pressure
3. Extra pressure of pressure cooker softens the beans
4. Internal energy is not lost while cooking in pressure cooker
The compressibility factor for H2 and He is usually:
1. >1
2. =1
3. <1
4. either of these
Boyle's law is applicable in :
1. Isobaric process
2. Isochoric process
3. Isothermal process
4. Adiabatic process
The correct value of the gas constant 'R' is close to
1. 0.082 L atm K
2. 0.082 L atm K-1 mol-1
3. 0.082 L atm-1 K mol-1
4. 0.082 L-1 atm-1 K mol
The number of molecules present in 1 mL of gas or vapor at STP is:
1. called Loschmidt's number
2. equal to 2.617 x 1019 per mL
3. both (1) and (2)
4. none of the above
600 cc of a gas at a pressure of 750 mm is compressed to 500 cc. Taking the temperature to remain constant, the increase in pressure is:
1. 150 mm
2. 250 mm
3. 350 mm
4. 450 mm
An ideal gas expands according to PV=constant. On expansion, the temperature of the gas:
1. Will rise.
2. Will drop.
3. Will remain constant.
4. Cannot be determined because the external pressure is not known.
The correct statement for an ideal gas equation is -
1. n is the number of molecules of a gas.
2. V denotes the volume of 1 mole of the gas.
3. n moles of a gas has a volume V.
4. p is the pressure of the gas when only one mole of the gas is present.
The ratio among most probable velocity, mean velocity, and root mean square velocity is given by
1. 1:2:3
2. 1:
3.
4.
The compressibility of a gas is less than unity at STP. Therefore:
1. Vm > 22.4 litre
2. Vm < 22.4 litre
3. Vm = 22.4 litre
4. Vm = 44.8 litre
The numerical value of cp -cv is equal to:
1. R
2. R/M
3. M/R
4. None of the above
In which case rate of diffusion is highest if all are present in the same container at the same temerature:
1. 4g H2
2. 32g O2
3. 22g CO2
4. 56g N2
Partial pressure of Hydrogen in a flask containing 2 gm of H2 and 32 gm of SO2 is:
1. 1/16 of total pressure
2. 1/2 of total pressure
3. 2/3 of total pressure
4. 1/8 of total pressure
At high pressure, the compressibility factor 'Z' is equal to-
1. Unity
2. 1-
3. 1+
4. Zero
The density of O2(g) is maximum at-
1. STP
2. 273 K and 2 atm
3. 546 K and 1 atm
4. 546 K and 2 atm
20 L of SO2 diffuses through a porous partition in 60s. Volume of O2 diffuse under similar condition in 30s will be:-
1. 12.14 L
2. 14.14 L
3. 18.14 L
4. 28.14 L
A gas diffuses four time quickly as oxygen. The molecular weight of gas is:
1. 2
2. 4
3. 8
4. 16
If density of vapours of a substance of molar mass 18 g/mole at 1 atm pressure and 500 K is
0.36 kg m–3 , then the value of Z for the vapours is-
(R = 0.082 L atm mole K–1)
1.
2.
3. 1.1
4. 0.9
A sample of water gas has a composition by volume of 50% H2, 45% CO and 5% CO2. Calculate the volume in litre at S.T.P. of water gas which on treatment with excess of stream will produce 5 litre H2. The equation for the reaction is : CO + H2O CO2+ H2
(1) 4.263 Litre
(2) 5.263 Litre
(3) 6.263 Litre
(4) 7.263 Litre
A 2 m long tube closed at one end is lowered vertically into' water until the closed end is flush with the water surface. See figure below. Calculate the water level height in the tube. (Barometric pressure –1 atm =10 m of hydrostatic water head, Temperature = 25°C, Density of, water = 1.00 g/ml. Neglect water vapour pressure).
(1) 1.01 m
(2) 0.29 m
(3) 1.71–m
(4) 0.92 m
A gas occupied a volume of 250 ml at 700 mm Hg pressure and 25°C. An additional pressure is required to reduce the gas volume to its 4/5th value at the same temperature is-
1. 225 mm Hg
2. 175 mm Hg
3. 150 mm Hg
4. 265 mm Hg
A sealed tube which can withstand a pressure of 3 atmosphere is filled with air at and 760 mm pressure. The tube will burst at -
1. 900°C
2. 627°C
3. 726°C
4. 1173°C
The pressure of 2 moles of an ideal gas at 546 K having volume 44.8 L is:
1. 2 atm
2. 3 atm
3. 4 atm
4. 1 atm
3.2 g of oxygen and 0.2 g of hydrogen are placed in a 1.12 litre flask at 0°C.
The total pressure of the gas mixture will be-
1. 1 atm
2. 4 atm
3. 3 atm
4. 2 atm
Equal weights of methane and oxygen are mixed in an empty container at 25°C. The fraction of the total pressure exerted by oxygen is-
1. 1/3
2. 1/2
3. 2/3
4.
The rate of diffusion of methane at a given temperature is twice that of gas X. The molecular weight of X is
(1) 64.0
(2) 32.0
(3) 4.0
(4) 8.0
The kinetic energy for 14 grams of nitrogen gas at 127°C is nearly (mol. mass of nitrogen = 28 and gas constant = 8.31JK–1mol–1)
(1) 1.0 J
(2) 4.15 J
(3) 2493 J
(4) 3.3 J
If the average velocity of N2 molecules is 0.3 m/s at 27°C, then the velocity of 0.6 m/s will take place at
(1) 273 K
(2) 927 K
(3) 1000 K
(4) 1200 K
A gas such as carbon monoxide would be most likely to obey the ideal gas law at-
1. High temperature and low pressure
2. Low temperature and high pressure
3. High temperature and high pressure
4. Low temperature and low pressure
A gaseous mixture was prepared by taking equal moles of CO and N2. If the total
pressure of the mixture was found 1 atmosphere, the partial pressure of the nitrogen
(N2) in the mixture is
1. 0.8 atm
2. 0.9 aim
3. 1 atm
4. 0.5 atm
What volume of oxygen gas (O2) measured at 0°C and 1 atm, is needed to burn completely 1 L of propane gas (C3H8) measured under the same conditions?
(1) 7L
(2) 6L
(3) 5L
(4) 10L
A certain volume of argon gas (Mol. wt. = 40) requires 45 s to effuse through a hole at a certain pressure and temperature. The same volume of another gas of unknown molecular weight requires 60s to pass through the same hole under the same conditions of temperature and pressure. The molecular weight of the gas is
(1) 53
(2) 35
(3) 71
(4) 120
Which of the following curves does not represent Boyle's Law
(1)
(2) `
(3)
(4)
The ratio of average molecular kinetic energy of to that of , both at 300 K is
(1) 1 : 1
(2) 7 : 2
(3) 176 : 1
(4) 2 : 7
X ml of gas effuses through a hole in a container in 5 seconds. The time taken for the effusion of the same volume of the gas specified below under ideal condition is
(1) 10 seconds :
(2) 20 seconds :
(3) 25 seconds :
(4) 55 seconds :
The valves X and Y are opened simultaneously. The white fumes of will first form at :
(1) A
(2) B
(3) C
(4) A, B and C simultaneously
A gas mixture consists of 2 moles of oxygen and 4 moles of a argon at temperature T. Neglecting all vibrational modes, the total internal energy of the system is –
(1) 4RT
(2) 5RT
(3) 15RT
(4) 11RT
Two flasks of equal volume are connected by a narrow tube (of negligible volume) at 27ºC and contain 0.70 mole of at 0.5 atm. One of the flasks is then immersed in a hot bath, kept at 127 ºC, while the other remains at 27 ºC. The final pressure is -
1. 5.714 atm
2. 0.5714 atm
3. 2.5214 atm
4. 5.5114 atm
Which is not correct curve for gay-lusacc's law?
1 .
2.
3.
4.
In two vessels of 1 litre each at the same temperature 1 g of and 1 g of are taken, for these:
1. values will be same
2. Kinetic energy per mol will be same
3. Total kinetic energy will be same
4. Pressure will be same
The van der Waals parameters for gases W, X, Y and Z are
Gas |
a (atm L2 mol-2) |
b(L mol-1) |
W |
4.0 |
0.027 |
X |
8.0 |
0.030 |
Y |
6.0 |
0.032 |
Z |
12.0 |
0.027 |
Which one of these gases has the highest critical temperature?
1. W
2. X
3. Y
4. Z
The excluded volume of a gas will be larger, if is:
1. small
2. large
3. equal to 1
4. less than unity