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401.

`I`, `II`, and `III` are three istherms, respectively, at `T_(1)`, `T_(2)`, and `T_(3)`. Temperature will be in order A. `T_(1)=T_(2)=T_(3)`B. `T_(1)ltT_(2)ltT_(3)`C. `T_(1)gtT_(2)gtT_(3)`D. `T_(1)gtT_(2)=T_(3)`

Answer» Draw a line at constant `P` parallel to volume axis. Take volume corresponding to each temperature.
From volume axis, `V_(1)gtV_(2)gtV_(3)`
Hence, `T_(1)gtT_(2)gtT_(3)`
402.

`I`, `II`, and `III` are three istherms, respectively, at `T_(1)`, `T_(2)`, and `T_(3)`. Temperature will be in order A. `T_(1) = T_(2)=T_(3)`B. `T_(1) lt T_(2) lt T_(3)`C. `T_(1) gt T_(2) gt T_(3)`D. `T_(1) gt T_(2) =T_(3)`

Answer» Correct Answer - C
As the temperature increases at constant `P`, volume of gas increases.
403.

Assertion: The coefficient of isothermal expansion at critical point is zero. Reason: `((delV_(c ))/(delT_(c )))_(P_(c ))=0`A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is false.D. If assertion is false but reason is true.

Answer» Correct Answer - A
`alpha=(((delV_(c ))/(delT_(c )))_(p,n))/(V_(c )), V_(c ), T_(c ). T_(c )` are constant at critical conditions.
404.

Assertion: On heating a sample of gas collision frequency increases. Reason: Heat is produced by the collision of gas molecules against each other.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is false.D. If assertion is false but reason is true.

Answer» Correct Answer - C
Collisions are perfectly elastic, however kinetic energy of molecule charges but average kinetic energy remains unchanged.
405.

Under what conditions will a pure sample of an ideal gas not only exhibit a pressure of `1 atm` but also a concentration of `1 mol litre^(-1)` `[R= 0.082` iltre atm `mol^(-1)K^(-1)]`A. at `STP`B. when `V=22.42L`C. when `T= 12 K`D. impossible under any condition

Answer» Correct Answer - C
`P=CRT, T=(P)/(RC)=(1xx12)/(1xx1)=12K`
406.

A certain sample of gas has a volume of `0.2` litre measured at `1 atm` pressure and `0^(@)C`. At the same pressure but at `273^(@)C`, its volume will beA. `0.4 litres`B. `0.8 litres`C. `27.8^(@)C`,D. `55.6` litres

Answer» Correct Answer - A
`(V_(1))/(V_(2))=(T_(1))/(T_(2))implies V_(2)= (T_(2))/(T_(1))V_(1)= (546 K)/(273 K)xx 0.2L= 0.4L`
407.

Under what conditions will a pure sample of an ideal gas not only exhibit a pressure of `1 atm` but also a concentration of `1 mol litre^(-1)` `[R= 0.082` iltre atm `mol^(-1)K^(-1)]`A. At STPB. When V = 22.4 LC. When T = 12 KD. Impossible under any conditions

Answer» Correct Answer - C
According to ideal gas equation,
`pV = n RT`
`p=(n)/(V)RT`
`"1 atm = 1 mol L"^(-1)xx0,082xxT`
`T=(1)/(0.082)=12K`
408.

For an ideal gas, pressure `(p)` and interal energy `(E )` per unit volume are related asA. `p = (3)/(2) E`B. `p = (2)/(3)E`C. `p = (1)/(2) E`D. `p = (1)/(3)E`

Answer» Correct Answer - B
According to the kinetic gas equation , `pV = (1)/(3) mnc^(2)`
` = (1)/(3) Mc^(2)` `(M = mn)`
` = (2)/(3).(1)/(2) Mc^(2)`
` = (2)/(3) E_(K)` `(E_(K) = (1)/(2) MC^(2))`
Dividing both sides by volume `(V)` , we get
`p = (2)/(3)E` `(E = (E_(K))/(V)`
Note that the internal energy of an ideal gas is equal to its kinetic energy because the potential energy of an ideal gas is zero as there is no intermolecular interaction between gas particles.
409.

For an ideal gas, pressure `(p)` and interal energy `(E )` per unit volume are related asA. `p=(2)/(3)E`B. `p=(3)/(2)E`C. `p=(1)/(2)E`D. `p=2E`

Answer» Correct Answer - A
The average translational kinetic energy of a gas molecule is `(1)/(2)mbar(u)^(2)` at a temperature, T. The total energy of the whole of the gas containing N molecules is
`E_(k)=(1)/(2)"m N"baru^(2)" …(i)"`
The kinetic gas equation is
`pV=(1)/(3)"m N"bar(u)^(2)" ...(ii)"`
`pV=(2)/(3)xx(1)/(2)mNbar(u)^(2)`
`pV=(2)/(3)E_(k)" ...(iii)"`
`"so, "p=(2)/(3)E_(k)" per unit volume"`
410.

The ratio among most probable velocity, mean velocity and root mean velocity is given byA. `1:2:3`B. `1:sqrt2:sqrt3`C. `sqrt2:sqrt3:sqrt((8)/(pi))`D. `sqrt2:sqrt((8)/(pi)):sqrt3`

Answer» Correct Answer - D
Most probable velocity, `U_(mp)=sqrt((2RT)/(M))`
`"Mean velocity, U"_(av)=sqrt((8RT)/(piM))`
`"Root mean square velocity, U"_(rms)=sqrt((3RT)/(M))`
so, `U_(mp):U_(av):U_(rms)=sqrt((2RT)/(M)):sqrt((8RT)/(piM)):sqrt((3RT)/(M))`
`=sqrt2:sqrt((8)/(pi)):sqrt3`
411.

A gas described by van der Waals equation .A. behaves similar to an ideal gas in the limit of large molar volumesB. behaves similar to an ideal gas in the limit of large pressures.C. is characterised by van der Waals co-efficients dependent the identity of the gas but independent of the temperatureD. has the pressure that is lower than the pressure exerted by the gas behaving ideally.

Answer» Correct Answer - A::C
are the correct options.
412.

Hydrogen gas obtained by electrolysis of `18g` of water is heated to `127^(@)C` at a pressure of `2 atm`. Calculate the volume it would occupy.

Answer» `H_(2)O overset(Electrolysis)(rarr) H_(2)+(1)/(2)O_(2)`
`1 mol` of `H_(2)O=18 g`
`implies 1 mol` of `H_(2)` at `STP=22.4 L` at `STP`
Volume of `H_(2)` at `127^(@)C(127+273=400 K)` and `2 atm` pressure is
`(P_(1)V_(1))/(T_(1))=(P_(2)V_(2))/(T_(2))`
`{:(P_(1)= 1 atm, P_(2)=2 atm),(T_(1)=273 K, T_(2)=400K),(V_(1)=22.4 L, V_(2)=?):}`
`V_(2)=(P_(1)V_(1)T_(2))/(P_(2)T_(1))=(1xx22.4xx400)/(2xx273)=16.4L`
413.

Which of the following statements are correct ?A. Z (compressibility factor)for ideal gas is independent of temperature and pressure.B. Z for ideal gas is greater than one.C. Z for non-ideal gas is either greater tha one or less than one as well as dependent on temperature and pressure.D. When `Z gt 1`, then force of attraction dominates over force of replusion.

Answer» Correct Answer - A::C
Both the statements are correct.
414.

Which expression gives average speed of gas molecules?A. `sqrt((8RT)/(M))`B. `(3RT)/(M)`C. `[(8RT)/(piM)]^(1//2)`D. `(8RT)/(3.14M)`

Answer» `mu_(av)=sqrt((8RT)/(piM))`
415.

At what temperature 28 g of `N_(2)` will occupy a volume of 20 litres at 2 atm ?A. ` 300.0 K`B. 487.2 kC. 289.6 KD. 283.8 K

Answer» Correct Answer - B
`PV=nRT` or `T=(PV)/(nR) " " (n=(m)/(M))`
`T=(2xx20xx28)/(28xx0.0821)=487.2 K`
416.

Which of the following pairs exhibit only dispersion forces as the only intermolecular forces ?A. `HBr` and `H_(2)S`B. `NH_(3)` and `C_(6)H_(6)`C. `Cl_(2)` and `CBr_(4)`D. `I_(2)` and `NO_(3)^(-)`

Answer» Correct Answer - C
Both `Cl_(2)` and `CBr_(4)` are nonpolar, so there are only dispersion forces between these molecules . Both `HBr` and `H_(2)S` are polar , so the forces between them are dipole -dipole forces. There are also dispersion forces between the molecules. `I_(2)` is nonpolar, so the forces between it and the ion `NO_(3)^(-)` are ion-induced forces and dispersion forces.
`NH_(3)` is polar and `C_(6)H_(6)` is nonpolar. The forces are dipole-induced dipoel forces and dispersion forces.
417.

The ratio between enrgies of `16 g` of `O_(2)` and `28 g` of `N_(2)` respectively at `300 K` will beA. `1:1`B. `1:2`C. `2:1`D. `4:7`

Answer» Correct Answer - B
Number of moles of `O_(2)= (16)/(32) =(1)/(2)`
Number of moles of `N_(2)=(28)/(28)=1`
Ratio between number of moles `(1)/(2):1`
`KE` will be in the ratio `1:2`
418.

The graph of P vs V is given at temperature and number of moles : The correct relationship is/areA. `T_(1) gt T_(2) gt T_(3)`B. `T_(1) lt T_(2) lt T_(3)`C. `n_(1) gt n_(2) gt n_(3)`D. `n_(3) gt n_(2) gt n_(1)`

Answer» Correct Answer - A::D
Both relationships are correct.
419.

Pick out the false statement.A. Vapour pressure of a liquids is the measure of the strength of intermolecular attractive forcesB. Liquid with stronger intermolecular interaction are more viscous than those with weaker intermolecular forceC. Vapour pressure of all liquids is same at their freezing pointsD. Both (a) and (b)

Answer» Correct Answer - C
Vapour pressure of all liquids are different at their freezing points.
420.

The approximate energy `(kJ mol^(-1))` of hydrogen bonding isA. `100 to 1000`B. `100 to 50`C. `0.1 to 10`D. `10 to 40`

Answer» Correct Answer - D
The approximate energy of van der Waals force is `0.1 to 10 kJ mol^(-1)`. The approximate energy of ionic bonding is `100 to 1000`.
421.

Which of the following properties of liquids arises(s) due to the molecular and thermal interaction?A. vapour pressureB. Surface tensionC. ViscosityD. All of these

Answer» Correct Answer - D
Vapour pressure, viscosity and surface tension of liquids arises due to the molecular and themal interaction.
422.

A curve drawn at costant temperature is called on isotherm. This shows the relationship between :A. P and `1/V`B. PV and VC. V and `1/P`D. P and V.

Answer» Correct Answer - D
423.

The figure helps to establish the relationship between force andA. area of contactB. velocity gradientC. coefficient of viscosityD. both (a) and (b) .

Answer» Correct Answer - D
This figure clearly helps to establish the relation that force is directly proportional to area of contact and velocity gradient.
`f prop A, f prop (du)/(dz)`
`therefore f prop A (du)/(dz)`
`f = eta A(du)/(dz)`
Where, `eta` = coefficient of viscosity.
A = Area of contact.
`(du)/(dz)`= velocity gradient.
424.

What is the relationship between thermal energy and intermolecular interaction energy of a substance in three states in terms of X and Y? `"Gas" rarr " Liquid" rarr " Solid"` `overset ("Predominance of X ") rarr` ` overset ("Predominance of Y") larr`A. X - Thermal energy , Y - Intermolecular interactionsB. X - Thermal energy , Y - Thermal energyC. X - Intermolecular interactions, Y - Thermal energyD. X - Intermolecular interactions, Y - Intermolecular interactions

Answer» Correct Answer - C
Intermolecular interactions increases from gas to solid. Thermal energy converts solids to liquids and liquids to gases.
425.

Which of the following elements is a monoatomic gas ?A. ChlorideB. RadomC. OxygenD. Hydrogen

Answer» Correct Answer - B
All the elements in group `8A`, the noble gases, are monoatomic gases.
426.

Hydrogen bonding is a particularly strong type of …… interactionA. dipole -induced dipoleB. dipole-dipoleC. ion-dipoleD. instantaneous dipole-induced dipole

Answer» Correct Answer - B
Hydrogen bond is a special type of dipole-dipole interaction between the `H` atom in a polar bond such as `N-H,O-H ,or F-H` , and an electronegative atom such as `O,N,or F` in another polar band . This interaction is written as
`A-H…B or A-H…..A`
`A` and `B` represent `O,N,or F,A-H` is one molecule or part of a molecule and `B` is a part of another molecule. The dotted line represents the hydrogen bond. Note that all these atoms possess at least one pair that can interact with the `H`atom in hydrogen bonding.
427.

Intermolecular forces areA. forces of attraction and repulsion between atoms or moleculesB. electrostatic forces between two oppositely charged ionsC. forces that hold the atoms of a molecular togetherD. both (2) and (3)

Answer» Correct Answer - A
Options `(2)` and `(3)` describe ionic and covalent bonds, respectively, and they are intramolecular forces.
428.

In a closed vessel, a gas is heated from `300 `K to `600 K` the kinetic energy becomes/remainsA. halfB. doubleC. sameD. four times

Answer» Correct Answer - B
`KE prop T`
429.

Which of the following represents the van der Walls equation for `n` moles of a real gas ?A. `(p + (na)/(V^(2)))(V - nb) = nRt`B. `(p + (a)/(nV^(2)))(V - nb) = nRt`C. `(p + (a)/(V^(2)))(V - b) = nRt`D. `(p + (n^(2)a)/(V^(2)))(V - b) = nRt`

Answer» Correct Answer - D
Real gases show deviations from the ideal gas law because the molecules interact with each other . At high pressures , the density of the gas increases and the molecules are much closer to one another. Then the intermolecular forces becomes significant enough to affect the motion of the molecules, and the gas no longer behaves ideally. Cooling a gas decreases the average kinetic energy of the molecules , which in a sense deprives the molecules of the drive they need to break away from their mutual attractive influences.
Consider the approach of a particular molecule toward the wall of a container. The intermolecular attractions exerted by its neighbors tend to soften the impact made by this molecules against the wall. The overall effect is a lower gas pressure than we would expect for an ideal gas.
`J.D.` van der Waals suggested that the pressure exerted by an ideal gas `(p_(ideal))` is related to the experimentally measured pressure `(p_(real))`
`p_(i de al) = underset(Observes pressure)(p_(real)) + underset(C o r rection term)((an^(2))/(V^(2))`
where `a` is a constant and `n` and `V` are the number of moles and volumes of the gas , respectively. The correction term for pressure `(an^(2)//v^(2))` can be understood as follows. The interaction between the molecules that gives rise to the nonideal behavior depends on how frequently any two molecules approach each other closely. The number of such encounters increases as the square of the number of molecules per unit volume , `(n//v)^(2)`, because the presence of each of the two molecules in a particular region is proportional to `n//v`. The quantity `a`, then , is just a proportional constant in the correction term of pressure. The quantiity `p_(i d e a l)` is the pressure we would measure if there were no intermolecular attractions. Repulsive forces (short-range interactions), which become significant at high pressure as molecules are almost in cotact , cause the molecules to behave as small but impenetrable sphere. Thus, another correction concerns the volume occupied by the gas molecules. The quantity `V` in the ideal gas equation `(pV = nRT)` represents the volume of the container. However, each molecule does occupy a finite, although small, intrinsic volume which becomes significant at high pressure , so the effective volume of the gas becomes `(V-nb)`, i.e., instead of moving in volume `V`, the molecules are now restricted to volume `(V-nb)` , where `n` is the number of moles of the gas and `b` is constant. The term `nb` represents the volume occupied by `n` moles of the gas. Having taken into account the correction for pressure and volume, we can rewrite the ideal gas equation as
`p_(i d e a l) V_(i d e a l) = nRt`
`ubrace((p+(an^(2))/(V^(2))))_("Correct presurre")ubrace((V-nb))_("Corrected volume")=nRT`
The van der Waals constants `a` and `b` are selected for each gas to give the best possible behavior. Thus, the pressure (or volume) calculated by the van der Waals equation is closer to the actual value than that calculated by the ideal gas equation.
430.

Which of the following interactions is not a part of the van der Walls forces?A. Dipole-dipole forcesB. Dipole-induced dipole forcesC. Dispersion forcesD. Ion-dipole forces

Answer» Correct Answer - D
The term van der Waals force is a general term for those intermolecular forces that include all forces except ion-dipole forces when are relatively strong. Ion-dipole forces occur between an ion(either a cation or an anion) and a polar molecule. The Dutch physicist J van der Waals was the first to suggest the importance of intermolecular forces.
431.

The `r.m.s`. velocity of hydrogen at `27^(@)C, R= 8.314 J mol^(-1)K^(-1)` is:A. `1.934 m//s`B. `19.34 m//s`C. `193.4 m//s`D. `1934 m//s`

Answer» Correct Answer - D
`U_(rms)=sqrt((3RT)/(M_(w)))implies sqrt((3xx8.314xx300)/(2xx10^(-3)))`
`U_(rms)= 1934 m//sec`
432.

Assetion: Carbon dioxide has greater value of root mean square velocity `mu_(rms)` than carbon monoxide. Reason: `mu_(rms)` is inversely proportional to molar mass.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is false.D. If assertion is false but reason is true.

Answer» Correct Answer - D
`mu_(rms)=sqrt((3RT)/(M))` is inversely related to molecular mass.
Therefore, `mu_(rms) (CO)gt mu_((rms))(CO)_(2)`.
433.

Under similar conditions, which of the following gas will have same value of `mu_(rms)` as `CO_(2)`?A. `NO`B. `C_(3)H_(8)`C. `CO`D. `N_(2)`

Answer» Correct Answer - B
`mu_(rms)=sqrt((3RT)/(M))`
`M_(CO_(2))+44g`
`M_(C_(3)H_(8))= 44g`
`:. (mu_(rma))CO_(2)= (mu_(rms))C_(3)H_(8)`
434.

Which of the following substances do not exist as a gas at `25^(@)C` and `1 atm`?A. `NH_(3)`B. `HCl`C. `NaCl`D. `CH_(4)`

Answer» Correct Answer - C
Ionic compounds do not exist as gases at `25^(@)C` and `1 atm ` because the cations and anions in an ionic compound are held together by very strong electrostatic forces. To overcome these attractions , we must supply a large amount of energy, thus ,ionic compounds have very high melting and boiling points.
The behaviour of molecular covalent compounds is more varied. Some are gases `(e.g., CO,CO_(2),HCl,NH_(3),and CH_(4))`, but the majority of molecular covalent compouns are liquids or solids under normal conditions.
In general the stronger the intermolecular forces, the less likely a compound can exist as a gas under normal conditions.
435.

Which of the following gases is a deadly poison ?A. `O_(2)`B. `H_(2)S`C. `SO_(2)`D. `HCN`

Answer» Correct Answer - D
`O_(2)` is essential for survival . Hydrogen sulphide `(H_(2)S)` and hydrogen cyanide `(HCN)` are deadly poisons. `HCN` is more poisonous. `SO_(2),O_(3),NO_(2)`, and `CO` are less toxic.
436.

At a given temperature, the density of an ideal gas is proportional toA. `p^(2)`B. `p`C. `sqrt(p)`D. `1//p`

Answer» Correct Answer - B
Rearranging the ideal gas equation `(pV = nRT)` , we have
`(n)/(V) = (p)/(RT)`
Replacing the number of moles `(n)` of the gas by
`(m("mass of the gas"))/(M("molar mass"))`
we get
`(m)/(MV) = (p)/(RT)`
Since density `(d)` is mass per unit volume , we can write
`d = (m)/(V) = (pM)/(RT)`
`:. d prop p`
437.

Calculate the volume occupied by 8.8 g of `CO_(2)` at `31.1^(@)C` and 1 bar pressure. R= 0.083 bar L `K^(-1)mol^(-1).`

Answer» Correct Answer - 5.05 L
It is known that,
`pV=m/MRT`
`rArr V=(mRT)/(Mp)`
Here,
m = 8.8 g
R= 0.083 bar `LK^(-1)mol^(-1)`
T = `31.1^(@)C` = 304.1 K
M =44 g
p = 1 bar
Thus, volume `(V)=(8.8xx0083xx304.1)/(44xx1)`
`" "=5.04806 L`
`" "5.05L`
Hence, the volume occupied is 5.05 L.
438.

Temperature at the foot of a mountain is `30^(@)C` and pressure is 760 mm whereas at the top of the mountain these are `0^(@)C` and 710 mm. Compare the densities of the air at the foot and at the to of the mountain.

Answer» Correct Answer - A::D
`d=(PM)/(RT)`, Hence, `(d_(1))/(d_(2))=(P_(1))/(T_(1))xx(T_(2))/(P_(2))=(760 mm)/(303 K)xx(273 K)/(710 mm)=(0.964)/(1)`
439.

There is a standard value of temperature and pressure at which the molar of a gas is 22.4 L . The correct values areA. 273 K atmB. 300 K , 760 mmC. `25 C^(@)` , 760 mmD. 373 K , 1 atm

Answer» Correct Answer - A
440.

How many elements are found as gases under normal conditions `(1 atm and 25^(@)C)` ?A. `21`B. `15`C. `11`D. `7`

Answer» Correct Answer - C
They are `H_(2),N_(2),O_(2),F_(2),Cl_(2)`, and all the elements of group `8A`.
441.

Which of the following relationships between partial pressure , volume and temperature is correct ? (i) `P = (nRT)/(V)` (ii) `P_("total") = P_(1) + P_(2) + P_(3)` (iii) `P_("total") = (n_(1) + n_(2) + n_(3)) (RT)/(V)`A. (i) and (ii)B. (i) and (iii)C. (ii) and (iii)D. (i) , (ii) and (iii)

Answer» Correct Answer - D
442.

At the same temperature and pressure, which of the following will have highest `KE` per moleA. `H_(2)`B. `O_(2)`C. `CH_(4)`D. All have same `KE`

Answer» Correct Answer - D
`KE= 3//2 nRT`
`KE= 3//2 nRT` for `1` mole
Since temperature is same, all the gases will have same kinetic energy
443.

The lowermost layer of the atmosphere is calledA. stratosphereB. troposphereC. mesophereD. thermosphere

Answer» Correct Answer - B
We spend our life in troposphere which is held to the surface of the earth by gravitational force. This thin layer of atmosphere is vital to our life. It shields us from harmful radiations and contains substances like dioxygen ,dinitrogen , carbon dioxide, water vapour, etc. The order is troposphere, statosphere, mesosphere, and thermosphere.
444.

If the average velocity of `N_(2)` molecules is `0.3 ms^(-1) at 27^(@) C` , then the velocity of `0.6 ms^(-1)` will take place atA. `273 K`B. `927 K`C. `1000 K`D. `1200 K`

Answer» Correct Answer - D
According to the kinetic molecular theory of gases, we have
`u_(aV) = sqrt((8RT)/(pi M))`
i.e., `u_(aV) prop sqrt(T)`
`:. ((u_(aV))_(1))/((u_(aV))_(2)) = sqrt((T_(1))/(T_(2)))`
`(0.3 m s^(-1))/(0.6 m s^(-1)) = sqrt((27 + 273))/(T_(2))`
`(1)/(2) = sqrt((300)/(T_(2)))` ltbrtgt or `(1)/(4) = (300)/(T_(2))`
or `T_(2) = 1200 K`
445.

The most probable velocity of a neutron at `20^(@)C` is nearby:A. `220 m//s`B. `2124 m//s`C. `22200 m//s`D. `22 m//s`

Answer» Correct Answer - B
`U_(mp)=sqrt((2RT)/(M))=sqrt((2xx8.314xx293)/(1.67xx10^(-27)xx6.023xx10^(23)))`
`= 2124 m//s`
446.

The molar volume of `CO_(2)` is maximum atA. NTPB. `0^(@)C` and 2.0 atmC. `127^(@)C` and 1atmD. `273^(@)C` and 2 atm

Answer» (c ) From `n=(nRT)/(P)`
At high T and belowp, V is high.
447.

Which of the following is a vapor?A. `H_(2)O`B. `HF`C. `HCl`D. `HI`

Answer» Correct Answer - A
A gas is a substance that is normally in the gaseous state at ordinary temperatures and pressures. Vapor is the gaseous form of any substance that is a liquid or a solid at normal temperatures and pressures. Thus , at `25^(@) C` and `1 atm` , we speak of water vapor and oxygen gas.
448.

A gas in a closed container will exert much higher pressure due to gravity at the bottom than at the top.

Answer» Correct Answer - F
449.

The viscosity of which of the following liquid is the maximum.A. waterB. glycolC. acetoneD. ethanol

Answer» Correct Answer - B
Extent of intermolecular hydrogen bonding increasing the viscosity.
450.

In the van der Waals equation `(P + (n^(2)a)/(V^(2)))(V - nb) = nRT` the constant a reflects the actual volume of the gas molecules.

Answer» Correct Answer - F