Van der Waal's Forces

Q.

Which of the following gas has the largest value of a Van Der Waals Constant?

1. ${\mathrm{CO}}_2$

2. ${\mathrm{NO}}_2$

3. ${\mathrm{H}}_2$

4. ${\mathrm{NH}}_3$

Q. Select the correct statements about van der Waals' constant ${}^{\prime }{b}^{\prime }$
1. It is excluded volume ​
2. ​​​​​​Its unit is ${\text{mol L}}^{-1}$
3. It depends on intermolecular force
4. ​​​​​​​Its value depends on molecular size

1. 2, 3
2. 1, 4
3. 2, 3, 4
4. 3, 4

Q. Arrange following in decreasing order of van der Waals' constant ${}^{\prime }{a}^{\prime }$ values: $H_{2}O,C{O}_2,Ar$

1. $H_{2}O>C{O}_2>Ar$
2. $Ar>H_{2}O>C{O}_2$
3. $Ar=H_{2}O>C{O}_2$
4. $H_{2}O>Ar>C{O}_2$

Q. What is the compressibility factor $\left(Z\right)$ for $0.02$ mole of a van der waal's gas at pressure of $0.1atm$. Assume the size of gas molecule is negligible.
(Given: $RT=20Latmmo{l}^{-1}$ and $a=1000atm{L}^{-2}mo{l}^{-1}$)

1. $2$
2. $1$
3. $0.02$
4. $0.5$

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. $4\text{g}$ of argon (Atomic mass = 40) in a bulb at a temperature of $TK$ has a pressure $P$ atm. When the bulb was placed in a hot bath at a temperature ${50}^{\circ }C$ more that the first one, $0.8\text{g}$ of the gas had to be removed to get the original pressure. $T$ is equal to:

1. $200\text{K}$
2. $100\text{K}$
3. $73\text{K}$
4. $510\text{K}$

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

1. 
2. 
3. 
4. 

Q. The compressibility factor for a gas under critical conditions is:

1. $\frac{8}{3}$
2. 1
3. $\frac{1}{4}$
4. $\frac{3}{8}$

Q. Statement–1: The value of the van der Waals constant ‘a’ is larger for $N{H}_3$ than $P{H}_3$.
Statement–2: Hydrogen bonding is present in $N{H}_3$

1. Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1
2. Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1
3. Statement-1 is True, Statement-2 is False
4. Statement-1 is False, Statement-2 is True

Q. For a van der Waal's gas $V_c=3b,P_c=\frac{a}{27b^2}$
$T_c=\frac{8_a}{27bR}$. Numerically the compressibility factor of a van der Waals gas at the critical points is:

1. $0.375$
2. $1$
3. $0.952$
4. $0.567$

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

1. Value of $a\text{for}C{l}_2>C_2{H}_6$
   Value of $b\text{for}C{l}_2<C_2{H}_6$
2. Value of $a\text{for}C{l}_2<C_2{H}_6$
   Value of $b\text{for}C{l}_2<C_2{H}_6$
3. Value of $a\text{for}C{l}_2>C_2{H}_6$
   Value of $b\text{for}C{l}_2>C_2{H}_6$
4. Value of $a\text{for}C{l}_2<C_2{H}_6$
   Value of $b\text{for}C{l}_2>C_2{H}_6$

Q. The reduced temperature for benzene is 0.7277 and its reduced volume is 0.40. Calculate the reduced pressure of benzene.

1. $40.358$
2. $30.358$
3. $20.358$
4. $10.358$

Q. Select the correct statements about van der Waals' constant ${}^{\prime }{b}^{\prime }$
1. It is excluded volume ​
2. ​​​​​​Its unit is ${\text{mol L}}^{-1}$
3. It depends on intermolecular force
4. ​​​​​​​Its value depends on molecular size

1. 2, 3
2. 1, 4
3. 2, 3, 4
4. 3, 4

Q. In Vander Waal's equation of state for a non-ideal gas, the term that accounts for intermolecular forces is

1. (V - b)
2. $(RT{)}^{-1}$
3. RT
4. $(P+\frac{a}{V^2})$

Q. Calculate the pressure exerted by one mole of $C{O}_2$ gas at 273 K if the van der Waal's constant, $a=3.592d{m}^{6}atmmo{l}^{-2}$. Assume that the volume occupied by $C{O}_2$ molecules is negligible.

1. $0.9922atm$
   
2. $1.9922atm$
3. $9.9222atm$
4. $0.1922atm$

Q. For compressibility factor, Z, which of the following is /are correct?

1. For most of the real gases Z decreases with P at the lower pressure
2. For most of the real gases Z increases with P at the higher pressure
3. For $H_2$ (g) and $He\left(g\right)$ Z increases with P at all the pressure & at room temperature
4. All of the above statements are correct

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. Calculate the temperature of the gas (in kelvin) if it obeys van der Waals' equation from the following data. A flask of $2.5\text{L}$ contains $10\text{mol}$ of a gas under $50\text{atm}$. Given $(a=5.46{\text{atm L}}^2{\text{mol}}^{-2},b=0.031{\text{L mol}}^{-1})$.

Q. Arrange following in decreasing order of van der Waals' constant ${}^{\prime }{a}^{\prime }$ values: $H_{2}O,C{O}_2,Ar$

1. $H_{2}O>C{O}_2>Ar$
2. $Ar>H_{2}O>C{O}_2$
3. $Ar=H_{2}O=C{O}_2$
4. $H_{2}O>Ar>C{O}_2$

Q. At high pressure, van der Waals' equation becomes:

1. $PV=RT$
2. $PV=RT+\frac{a}{V}$
3. $PV=RT-\frac{a}{V}$
4. $PV=RT+Pb$