Van der Waal's Forces

Q.

a and b are van der Waals constants. Which gas will liquefy easily?

1. Larger values of a and b

2. Smaller values of a, but larger values of b

3. Smaller values of a and b

4. Larger values of a, but smaller values of b

Q. What is the value of compressibility factor in terms of vander waal cons†an t at different conditions of pressure and volume?Why is Z>1 for H2 and He gas

Q.

London force increase with increase in molecular weights. (True or False)

1. True

2. False

Q. In Real Gas equation, where Pideal=Preal+Pcorrection Pcorrection is intermolecular forces of attraction and if we add it in Preal it will be less then Pideal. So why isnt the equation is Pideal=Preal-Pcorrection where intermolecular forces of attraction is deducted and it then becomes equal to Pideal?

Q. The relative strength of interionic/ intermolecular forces in decreasing order is:

1. ion-dipole > dipole-dipole > ion-ion
2. ion-dipole > ion-ion > dipole-dipole
3. dipole-dipole > ion-dipole > ion-ion
4. ion-ion > ion-dipole > dipole-dipole

Q. one mole of an ideal gas undergoes a process P=Pnot/2+Vnot/V(where Pnot and Vnot are constant).change in temperature of the gas when volume is changed from V=Vnot to V =3Vnot is (in terms of Pnot, Vnot, R

Q. 'a' and 'b' are van der Waals' constants for gases. Chlorine is more easily liquefied than ethane because

1. a and b for $C{l}_2>a$ and b for $C_2{H}_6$
2. a and b for $C{l}_2<a$ and b for $C_2{H}_6$
3. a for $C{l}_2>a$ for $C_2{H}_6$ but b for $C{l}_2>b$ for $C_2{H}_6$
4. a for $C{l}_2>a$ for $C_2{H}_6$ but b for $C{l}_2<b$ for $C_2{H}_6$

Q. The compressibility factor for one mol of a vanderwalls gas at 0 degree c and 100atm pressure is .5 then what will be the volume of 2 mols of this gas

Q. The value of equilibrium cons†an t for self-ionization of water is - 1)55.5×10^{-18} 2)5.55×10^{-18} 3)3.25×10^{-18} 4)1×10^{-1

Q.

The weakest bond among the following is _____.

1. Metallic

2. Ionic

3. Covalent

4. Van der Waals

Q. Oxygen and hydrogen are present in 2:1 molar ratio at 10 atm pressure find ratio of rate of diffusion . also find mole of gases diffused Find ratio of gas diffused from H2 to O2 if equal mass of gas is present

Q. The constant '$a$' in van der Waals' equation is maximum in:

1. $He$
2. $H_2$
3. $O_2$
4. $N{H}_3$

Q.

Definition of gas : Something which does not have definite volume or shape.

But , we can measure the volume of gas , say, 1 mole of gas contains 22.4l of gas.

How is this possible.?

Q. van der Waals' constant '$b$' of $Ar$ is $3.22\times {10}^{-5}{\text{m}}^3{\text{mol}}^{-1}$.Calculate the molecular diameter(in $nm$) of $Ar$.

Q. For one mole of a van der Waal's gas when b = 0 and T = 300 K, the PV vs $\frac{1}{V}$ plot is shown below. The value of the van der Waal's constant a $\left({\text{atm. liter}}^2{\text{mol}}^{-2}\right)$ is:

1. 1
2. 1.5
3. 4.5
4. 3

Q.

This section contains 1 Assertion-Reason type question, which has 4 choices (a), (b), (c) and (d) out of which ONLY ONE is correct.

इस खण्ड में 1 कथन-कारण प्रकार का प्रश्न है, जिसमें 4 विकल्प (a), (b), (c) तथा (d) दिये गये हैं, जिनमें से केवल एक सही है।

A : At intermediate pressures for most gases compressibility factor is less than 1.

A : मध्यवर्ती दाब पर, अधिकांश गैसों के लिए संपीड्यता कारक 1 से कम होता है।

R : At intermediate pressures, attractive forces dominate in most of the gases.

R : मध्यवर्ती दाब पर, अधिकांश गैसों में आकर्षी बल प्रभावी होते हैं।

1. Both (A) and (R) are true and (R) is the correct explanation of (A)
   
   (A) तथा (R) दोनों सही हैं तथा (R), (A) का सही स्पष्टीकरण है
2. Both (A) and (R) are true but (R) is not the correct explanation of (A)
   
   (A) तथा (R) दोनों सही हैं लेकिन (R), (A) का सही स्पष्टीकरण नहीं है
3. (A) is true but (R) is false
   
   (A) सही है लेकिन (R) गलत है
4. (A) is false but (R) is true
   
   (A) गलत है लेकिन (R) सही है

Q. Calculate pressure exerted by 1 mole of a van der Waal gas at a temperature of $\frac{8}{0.0821}K$ in a $\frac{1}{2}L$ container, if the volume of the molecule is assumed to be negligible and van der Waal's constant $a=2{\text{atm L}}^2{\text{mol}}^{-2}$

Q. Which of the following represents van der Waals gas below the critical temperature?

1. 
2. 
3. 
4. 

Q. Calculate pressure exerted by 1 mole of a van der Waal gas at a temperature of $\frac{8}{0.0821}K$ in a $\frac{1}{2}L$ container, if the volume of the molecule is assumed to be negligible and van der Waal's constant $a=2{\text{atm L}}^2{\text{mol}}^{-2}$

Q. Find the temperature ($\text{in K}$) at which 3 moles of $S{O}_2$ will occupy a volume of $10\text{L}$ at a pressure of $15\text{atm}$.
[ $a=6.71{\text{atm litre}}^2{\text{mol}}^{-2}$; $b=0.0564{\text{litre mol}}^{-1}$]

Q. What does compressibility factor of a gas tell us?

Q. Which of the following represents van der Waals gas below the critical temperature?

1. 
2. 
3. 
4. 

Q. Which one of the following has the highest boiling point?

1. $He$
2. $Ne$
3. $Kr$
4. $Xe$

Q. The compressibility factor for one mole of Vander Waals constant gas at 0C and 100 atm pressures is to be
0.5. Assuming that the volume of a gas molecule is negligible, calculate the Vander Waals constant a.