States of Matter
The isobars of one mole of an ideal gas were obtained at three different pressure ( $p_1, p_2$ and $p_3$ ). The slopes of these isobars are $m_1, m_2$ and $m_3$ respectively. If $p_1 < p_2 < p_3$, then the correct relation of the slopes is
$m_1 > m_2 > m_3$
$m_1 < m_2 < m_3$
$m_1>m_3>m_2$
$m_1=m_2=m_3$
The force $(F)$ required to maintain the flow of layers of a liquid is equal to
( $A=$ area of contact of layers
$d z=$ distance between the layers
$d u=$ change in velocity
$\eta=$ coefficient of viscosity)
$\eta \frac{d u}{d z} \cdot \frac{1}{A}$
$\eta \frac{d z}{d u} \cdot A$
$\eta \mathrm{A} \frac{d u}{d z}$
$\eta \frac{d z}{A} \cdot \frac{1}{d u}$
At 298 K , a flask ' $A$ ' of unknown volume $(V)$ contains oxygen at 5 atm . Another flask ' $B$ ' of volume 2 L contains helium at 3 atm . Two flasks are connected together by a small tube of zero volume. After the two gases are completely mixed, if the resulting mixture is found to have the mole fraction of oxygen as 0.2 , the volume of flask ' $A$ ' (in L ) is
(Assume oxygen and helium as ideal gases)
0.1
0.3
0.2
0.4
At $T(\mathrm{~K})$ root mean square (rms) velocity of argon (molar mass $40 \mathrm{~g} \mathrm{~mol}^{-1}$ ) is $20 \mathrm{~ms}^{-1}$. The average kinetic energy of the same gas at $T(\mathrm{~K})$ (in $\mathrm{J} \mathrm{mol}^{-1}$ ) is
8
16
4
2
Two vessels are filled with ideal gases $A$ and $B$ and are connected through a pipe of zero volume as shown in figure. The stop cock is opened and the gases are allowed to mix homogeneously and the temperature is
kept constant. The partial pressures of $A$ and $B$ respectively ( in atm ) are
$8.0,5$
$9.6,4$
$6.4,4$
$4.8,2$
The RMS velocity of dihydrogen is $\sqrt{7}$ times more than that of dinitrogen. If $T_{\mathrm{H}_2}$ and $T_{\mathrm{N}_2}$ are the temperatures of dihydrogen and dinitrogen, then the correct relationship between them is
$T_{\mathrm{H}_2}=T_{\mathrm{N}_2}$
$T_{\mathrm{H}_2}>T_{\mathrm{N}_2}$
$T_{\mathrm{H}_2}=\sqrt{7} T_{\mathrm{N}_2}$
$T_{\mathrm{H}_2}=\frac{T_{\mathrm{N}_2}}{2}$
2.0 g of $\mathrm{H}_2$ diffuses through a porous container in 10 minutes. How many grams of $\mathrm{O}_2$ would diffuse from the same container in the same time under similar conditions?
2.0
4.0
16.0
8.0
At $T(\mathrm{~K})$, the $u_{\mathrm{rms}}$ of $\mathrm{CO}_2$ is $412 \mathrm{~ms}^{-1}$. What is its kinetic energy (in $\mathrm{kJ} \mathrm{mol}^{-1}$ ) at the same temperature ?
$ \left(\mathrm{CO}_2=44 \mathrm{u}\right) $
3.7343
7.4687
14.9374
3734.3
Identify the correct graph for an ideal gas $(y$-axis $=$ compressibility factor, $Z: x$-axis $=$ pressure, $p)$




Identify the correct statements from the following:
I. Glass is an extremely viscous liquid.
II. Increase in temperature decreases the surface tension of liquids.
III. Compressibility factor for an ideal gas is zero.
I, II and III
I and II only
I and III only
II and III only
The correct equation for one mole of a real gas is $a, b$ are constants)
$\left(p+\frac{a}{V^2}\right)(V-b)=R T$
$\left(p-\frac{a}{V^2}\right)(V-b)=R T$
$\left(p+\frac{a}{V^2}\right)(V+b)=R T$
$\left(p+\frac{a}{V}\right)(V-b)=R T$
$A$ and $B$ are ideal gases. At $T(\mathrm{~K}), 2 \mathrm{~L}$ of ' $A^{\prime}$ 'with a pressure of 1 bar is mixed with 4 L of ' $B$ ' with a pressure $p_B$ bar in a 100 L flash. The pressure exerted by gaseous mixture is 0.1 bar. What is the value of $p_B$ in bar?
2
0.04
0.02
1
- Consider the following
Statement I If thermal energy is stronger than intermolecular forces, the substance prefers to be in gaseous state.
Statement II At constant temperature, the density of an ideal gas is proportional to its pressure.
The correct answer is
Statement-I is correct, but Statement-II is not correct.
Statement-I is not correct, but Statement-II is correct.
Both Statement-I and Statement-II are correct.
Both Statement-I and Statement-II are not correct.
At $27^{\circ} \mathrm{C}, 1 \mathrm{~L}$ of $\mathrm{H}_2$ with a pressure of 1 bar is mixed with 2 L of $\mathrm{O}_2$ with a pressure of 2 bar in a 10 L flask. What is the pressure exerted by gaseous mixture in bar? (Assume $\mathrm{H}_2$ and $\mathrm{O}_2$ as ideal gases)
4
0.05
1
0.5
Choose the incorrect statement from the following.
At Boyle temperature a real gas obeys ideal gas law over an appreciable range of pressure.
Critical temperature of $\mathrm{CO}_2$ is $27.5^{\circ} \mathrm{C}$.
Above critical temperature, a real gas behaves like an ideal gas.
At room temperature and 1 atm pressure the compressibility factor $(Z)$ for $\mathrm{H}_2$ gas is greater than 1 .
$\frac{x}{15}$
$\frac{4 x}{15}$
$\frac{8 x}{15}$
$\frac{2 x}{15}$
At $T(\mathrm{~K})$, hydrogen and oxygen gases are mixed in the ratio of $1: 2$ by mass in a closed vessel of volume ' $V$ ' litres. If the total pressure of gaseous mixture is ' $p$ ' atm, the partial pressure of oxygen (in atm) is
$\frac{p}{9}$
$9 p$
$\frac{8 p}{9}$
$\frac{p}{6}$
At what temperature (in K ) the rms velocity of $\mathrm{SO}_2$ molecules is equal to rms velocity of $\mathrm{O}_2$ molecules at $27^{\circ} \mathrm{C}$ ?
300
1200
600
900
For one mole of an ideal gas an isochore is obtained. The slope of the isochore is $0.082 \mathrm{~atm} \mathrm{~K}^{-1}$. What will be its pressure (in atm) when the temperature is $12.2 \mathrm{~K} ?\left(R=0.082 \mathrm{~L} \mathrm{~atm} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}\right)$
10.0
0.1
1.0
0.5
At $\mathrm{T}(\mathrm{K})$, a gaseous mixture contains $\mathrm{H}_2$ and $\mathrm{O}_2$. The total pressure of the mixture is 2 bar. The partial pressure of $\mathrm{H}_2$ is 1.778 bar. What is the weight $(w / w)$ percentage of $\mathrm{H}_2$ in the mixture?
66.67
33.33
80.00
20.00
480
240
720
120
$ \text { Which of the following is correct for an ideal gas? } $



At 256 K , rms speed of $\mathrm{SO}_2$ gas molecules is $3.16 \times 10^2 \mathrm{~ms}^{-1}$. What is the most probable velocity (in $\mathrm{ms}^{-1}$ ) of same gas at same temperature?
$2.911 \times 10^2$
$2.58 \times 10^2$
$5.16 \times 10^2$
$129 \times 10^2$
Consider the following
Statement-I : If the intermolecular forces are stronger than thermal energy, the substance prefers to be in gaseous state.
Statement-II : Among all elements, the total number of elements available as gases at room temperature is 10 .
The correct answer is
Both Statement-I and Statement-II are correct.
Both Statement-I and Statement-II are not correct.
Statement-I is correct, but Statement-II is not correct.
Statement-I is not correct, but Statement-II is correct.
Identify the conditions at which van der Waals' equation of state changes to ideal gas equation.
high temperature and high pressure
low temperature and high pressure
high temperature and low pressure
Iow temperature and low pressure
At STP, a closed vessel contains I mole each of He and $\mathrm{CH}_4$. Through a small hole, 2 L of He and LL of $\mathrm{CH}_4 \mathrm{WHS}$ escaped from vessel in ' $t$ ' minutes. What are the mole fractions of He and $\mathrm{CH}_4$ respectively remaining in the vessel? ( Assume He and $\mathrm{CH}_4$ as ideal gases. At STP one mole of an ideal gas occupies 22.4 L of volume.)
At $T(\mathrm{~K})$, the $p, V$ and $u_{\mathrm{rms}}$ of 1 mole of an ideal gas were measured. The following graph is obtained. What is it slope ( $m$ )?
( $x$-axis $=p V: y$-axis $u_{\mathrm{rms}}^2, M=$ Molar mass $)$
The RMS velocity ( $u_{\mathrm{rms}}$ ) of one mole of an ideal gas was measured at different temperatures and the following graph is obtained. What is the slope $(m)$ of straight line ?
$ \begin{aligned} & \left(X \text {-axis }=T(\mathrm{~K}): Y \text {-axis }=\left(u_{\mathrm{rms}}\right)^2: M=\right.\text { molar mass : } \\ & R=\text { gas constant } \end{aligned} $
Two statements are given below.
Statement I : Viscosity of liquid decreases with increase in temperature.
Statement II : The units of viscosity coefficient are pascal.
The correct answer is
Two statement are given below.
Statement I : The ratio of the molar volume of a gas to that of an ideal gas at constant temperature and pressure is called the compressibility factor.
Statement II : The rms velocity of a gas is directly proportional to square root of $T(\mathrm{~K})$.
The correct answer is
Given below are two statements.
Statement I : Viscosity of liquid decreases with increase in temperature.
Statement II : The units of viscosity are $\mathrm{kg} \mathrm{m}^{-1} \mathrm{~s}^{-1}$.
The correct answer is
Two containers $A$ and $B$ contain $\mathrm{CO}_2$ gas. Pressure, volume and absolute temperature of the gas in $A$ are 4 times more compared to that in $B$. The mass of the gas in $B$ is $x \mathrm{~g}$, then the mass of the gas in $A$ will be
$\frac{x}{2} g$
$4 \times g$
$2 \times \mathrm{g}$
$16 \times \mathrm{g}$
The rate of diffusion of a gas $A$ is $\sqrt{5}$ times more than that of gas $B$. If the molar mass of $A$ is $x \mathrm{~g} \mathrm{~mol}^{-1}$, the molar mass of $B$ (in $\mathrm{g} \mathrm{mol}^{-1}$ ) is
$4 x$
$5 x$
$16 x$
$25 x$



