Mole Fraction

Q. The mole fraction of a solute in a 1 m aqueous solution is:

1. 0.0177
2. 0.177
3. 0.0344
4. 1.77

Q.

The vapour density of a mixture containing $N{O}_2$ and $N_2{O}_4$ is $27.6$. Mole fraction of $N{O}_2$ in the mixture is:

1. $0.2$
2. $0.4$
3. $0.6$
4. $0.8$

Q. Liquids A and B form ideal solution over the entire range of composition. At temperature T, equimolar binary solution of liquids A and B has a vapour pressure of 45 Torr. At the same temperature, a new solution of A and B having mole fractions $x_A$ and $x_B$, respectively, has a vapour pressure of 22.5 Torr. The value of $\frac{x_A}{x_B}$ in the new solution is. (given that the vapour pressure of pure liquid A is 20 Torr at temperature T)

Q. Calculate the mole fraction of 30% by mass benzene in a solution with carbon tetrachloride.

1. 0.542
2. 0.458
3. 0.518
4. 0.324

Q. What is the mole fraction of the solute in a 1.00 molal aqueous solution?

1. 0.0354
2. 0.0177
3. 0.177
4. 1.77

Q.

Find out the molarity of water if its density is $1000{\mathrm{Kgm}}^{-3}$.

Q. A solution is made with Solvent A (molar mass 40 g/mol) by slowly adding solute B. A curve is plotted between molality of the solution vs $\frac{x_B}{x_A}$ where $x_B$ and $x_A$ represents the mole fraction of solute and solvent respectively.
Calculate the slope of the curve.

1. 10 mol/g
2. 10 g/mol
3. 25 g/mol
4. 25 mol/g

Q. An aqueous solution is prepared by diluting 3.30 mL of acetone (density = 0.789 g/mL) to get the final volume of 75 mL. Find the mole fraction of acetone. (Assume no volume change on mixing).

1. 0.11
2. 0.1
3. 0.001
4. 0.01

Q. If 10% (w/w) aqueous solution of $K_{2}C{O}_3$ is kept in a container whose volume capacity is 100 L then, mole fraction ($x_{K_{2}C{O}_3}$) is equal to:

1. 0.0254
2. 0.0138
3. 0.0188
4. 0.0368

Q. The mole fraction of solute in some solution is $\frac{1}{n}$. If $50\%$ of the solute molecules dissociates into two parts and remaining $50\%$ get dimerized and new mole fractions of solvent become $\frac{4}{5}$ Find the value of n

Q.

The vapour density of a mixture containing $N{O}_2$ and $N_2{O}_4$ is $27.6$. Mole fraction of $N{O}_2$ in the mixture is:

1. $0.2$
2. $0.4$
3. $0.6$
4. $0.8$

Q.

Calculate the mass of $H_{2}O$ and $C_2{H}_{5}OH$ required to make 640 gm mixture having $X_{H_{2}O}$ and $X_{C_2{H}_{5}OH}$ equal to 0.5

1. 640 gm, 640 gm

2. 180 gm, 180 gm

3. 180 gm, 460 gm

4. 460 gm, 180 gm

Q. Electrons are precisely distinguished by what are known as quantum numbers. i.e., n, l, m_l and m_s. n defines the shell. There are n subshells in the n^th shell. There are (2l + 1) orbitals of each type in subshell that is, one s-orbital (l = 0), three p orbitals (l = 1), five d orbitals (l = 2) and seven f orbitals (l = 3) per subshell. m_l designates the orientation of the orbital and for a given value of l, m_l has (2l + 1) values. m_s refers to orientation of spin of the electrons.

इलेक्ट्रॉनों को परिशुद्ध रूप से क्वाण्टम संख्याओं अर्थात् n, l, m_l एवं m_s द्वारा विभेदित किया जाता है। n कोश को परिभाषित करता है। n^th कोश में n उपकोश होते हैं। एक उपकोश में प्रत्येक प्रकार के (2l + 1) कक्षक होते हैं जैसे प्रति उपकोश में एक s-कक्षक (l = 0), तीन p कक्षक (l = 1), पाँच d कक्षक (l = 2) तथा सात f कक्षक (l = 3) होते हैं। m_l कक्षक के अभिविन्यास को निर्धारित करता है तथा l के दिए गए मान के लिए m_l के मान (2l + 1) होते हैं। m_s इलेक्ट्रॉनों के चक्रण के अभिविन्यास का निर्धारण करता है।
Q. Total number of orbitals possible in 4^th shell is

प्रश्न -4^th कोश में संभव कक्षकों की कुल संख्या है

1. 2
2. 9
3. 10
4. 16

Q. The partial pressure of ethane over a saturated solution containing $6.56\times {10}^{-2}g$ of ethane in water is 1 bar. If the solution contains $5\times {10}^{-2}g$ of ethane, then what shall be the partial pressure of the gas ?

Assume: $n_{H_{2}O}>>n_{ethane}$

1. $0.2bar$
2. $1.55bar$
3. $0.76bar$
4. $2bar$

Q. Paragraph for below question
नीचे दिए गए प्रश्न के लिए अनुच्छेद

Hydrogen bonding play a critical role in deciding the boiling point of a molecule. Consider ortho and para nitro phenol.

हाइड्रोजन बन्धन की एक अणु के क्वथनांक निर्धारण में महत्वपूर्ण भूमिका होती है। ऑर्थो और पेरा नाइट्रोफीनॉल पर विचार कीजिए।


Q. If –OH is replaced by –NH₂ in both compounds I and II, then the order of boiling point would be

प्रश्न - यदि I तथा II दोनों यौगिकों में –OH को –NH₂ द्वारा प्रतिस्थापित कर दिया जाता है, तो क्वथनांक का क्रम होगा

1. I > II
2. I < II
3. I = II
4. Cannot be predicted
   
   निर्धारित नहीं किया जा सकता

Q.

The number of moles present in $24.5gms$ of $H_{2}S{O}_4$ is

1. 4

2. 2.5

3. 0.5

4. 0.25

Q. Equal weights of methane and oxygen are mixed in an empty container at ${25}^{o}C.$ The fraction of the total pressure exerted by oxygen is
(IIT-JEE, 1981)

1. $\frac{1}{3}$
2. $\frac{1}{2}$
3. $\frac{2}{3}$
4. $\frac{1}{3}\times \frac{273}{298}$

Q. Liquids A and B form ideal solution over the entire range of composition. At temperature T, equimolar binary solution of liquids A and B has vapour pressure 45 torr. At the same temperature, a new solution of A and B having mole fractions$X_A$ and $X_B$ , respectively, has vapour pressure of 22.5 torr. The value of $X_A$ / $X_B$ in the new solution is:
(Given that the vapour pressure of pure liquid A is 20 Torr at
temperature T)

Q. Liquids A and B form ideal solution over the entire range of composition. At temperature T, equimolar binary solution of liquids A and B has vapour pressure 45 torr. At the same temperature, a new solution of A and B having mole fractions$X_A$ and $X_B$ , respectively, has vapour pressure of 22.5 torr. The value of $X_A$ / $X_B$ in the new solution is:
(Given that the vapour pressure of pure liquid A is 20 Torr at
temperature T)

Q. If 10% (w/w) aqueous solution of $K_{2}C{O}_3$ is kept in a container whose volume capacity is 100 L then, mole fraction ($x_{K_{2}C{O}_3}$) is equal to:

1. 0.0188
2. 0.0368
3. 0.0254
4. 0.0138

Q.

If 22g of ${\mathrm{CO}}_2$ occupy V litre at STP then what volume would 32g of ${\mathrm{O}}_2$ occupy at STP? Justify your answer.

Q. An ideal gas mixture of ethane $\left(C_2{H}_6\right)$ and ethene $\left(C_2{H}_4\right)$ occupies 28 litres at 1 atm and 273 K. The mixture reacts completely with 128 g of $O_2$ to produce $C{O}_2$ and $H_{2}O$. The mole fraction of $C_2{H}_6$ in the mixture is:

1. 0.6
2. 0.4
3. 0.5
4. 0.8

Q.

Calculate the volume of $320\mathrm{g}$of ${\mathrm{SO}}_2$ at stp.

(Atomic mass : $S=32$and $O=16$ ).

Q. Unit of mole fraction is

1. Moles/litre
2. $Moles/litr{e}^2$
3. Moles - litre
4. Dimensionless

Q. Equal weights of methane and oxygen are mixed in an empty container at ${25}^{o}C.$ The fraction of the total pressure exerted by oxygen is
(IIT-JEE, 1981)

1. $\frac{1}{3}$
2. $\frac{1}{2}$
3. $\frac{2}{3}$
4. $\frac{1}{3}\times \frac{273}{298}$

Q. Equal weights of methane and oxygen are mixed in an empty container at ${25}^{o}C.$ The fraction of the total pressure exerted by oxygen is
(IIT-JEE, 1981)

1. $\frac{1}{3}$
2. $\frac{1}{2}$
3. $\frac{2}{3}$
4. $\frac{1}{3}\times \frac{273}{298}$

Q.

Mole fractions of A and B in a mixture in which $6.023\times {10}^{23}$ molecules of A and $10.4\times {10}^{23}$ molecules of B are present are:

1. 0.37, 0.37

2. 063, 0.37

3. 0.37, 0.63

4. 0.63, 0.63