Liquids in Liquids

Q.

Boiling point of water of $750\text{mm Hg}$ is ${99.63}^{\circ }\text{C}$. How much sucrose is to be added to $500\text{g}$ of water such that it boils at ${100.02}^{\circ }\text{C}$?

Molar elevation constant for water is $0.52{\text{Kkgmol}}^{-1}$.

1. $121.7\text{g}$
2. $128.25\text{g}$
3. $1217\text{g}$
4. $12825\text{g}$

Q. 14. the lowering of vapour pressure of 0.1M aqueous solutions of NaCl , K2SO4 and CuSO4 are a) all equal b) in the ratio of 1:1:1.5

Q. An azeotropic solution of two liquids has a boiling point lower than either of them when it:

1. Shows a negative deviation from Raoult’s law
2. Shows no deviation from Raoult’s law
3. Shows positive deviation from Raoult’s law
4. Is saturated

Q.

The crystalline solids are:

1. anisotropic

2. Isotropic

3. Enantiotropic

4. Atropic

Q.

Fill in the blank.
Boiling point of solution containing a non volatile solute is always ---- the boiling point of pure solvent in which solution is prepared.

1. Same as

2. Higher than

3. Lower than

4. Initally it is higher than it becomes lower

Q.

The relative lowering of the vapour pressure of an aqueous solution containing a non-volatile solute is $0.0125$. The molality of the solution is:

1. $0.07$

2. $0.30$

3. $0.70$

4. $0.125$

Q. 111.1g of the non-volatile solute, urea needs to be dissolved in 100 g of water, in order to decrease the vapour pressure of water by 25%. The molarity of the solution will be:

1. 18.92 M
2. 19.52 M
3. None of the above
4. 18.52 M

Q.

For a solution to form positive deviation, the solute-solvent interactions must be less than solute-solute and solvent-solvent interactions, making it easier for the molecules to escape in its pure form.still, why does the vapour pressure of the solution showing positive deviation increase compared to the pure form?

Q. An aqueous solution of methanol in water has vapour pressure

1. More than that of water
2. Less than that of water
3. Equal to that of water
4. Equal to that of methanol

Q. Which of the following is not hygroscopic
1) NaCl
2) MgCl2
3) CaCl2
4) LiCl

Q.

Melting points of three solids X, Y and Z are 298 K, 314 K and 398 K respectively. Arrange these in increasing order of inter particle forces of attraction?

Q. why NaCl is more soluble then AgCl ?

Q.

What happens when vapour pressure is greater than atmospheric pressure?

Q. 38. The vapour pressure of a solution having solid as solute and liquid as solvent is 1) directly proportional to mole fraction of solvent 2) inversely proportional to mole fraction of solvent 3) directly proportional to mole fraction of the solute 4) inversely proportional to mole fraction of the solute

Q.

What is the boiling point of sugar solution at atmospheric pressure? How do we calculate the boiling point elevation of sugar solution?

Q. 100ml of liquid A and 25ml of liquid B is mixed to give a solution which does not obey Raoults law . The volume of the solution (1) will be 125 ml (2) can be ≥ or ≤ than 125 ml (3) can be ≥ , = or ≤ than 125 ml (4) will be less than 125 ml

Q.

The advantage of alcohol as thermometric liquid is due to its

1. Low boiling point.

2. Low freezing point.

3. High vapour pressure.

4. All the above.

Q. For an equilibrium $H_{2}O\left(s\right)\rightleftharpoons H_{2}O\left(l\right)$ which of the following statement is true?

1. The pressure changes do not affect the equilibrium
2. More of ice melts if pressure on the system is increased
3. More of liquid freezes if pressure on the system is increased
4. The pressure changes may increase or decrease the degree of advancement of the reaction depending upon the temperature of the system

Q.

What is mole fraction and what will be the it's effect on solubility if I decrease it . ??and why

Q. Which of the following solvents can dissolve oil?

1. $H_{2}O$
2. $C{S}_2$
3. ethanol
4. butane

Q.

Discuss how air pressure affects the rate of evaporation?

Q. For a solution formed by mixing liquids $\text{L}$ and $\text{M}$, the vapour pressure of $\text{L}$ plotted against the mole fraction of $\text{M}$ in solution is shown in the following figure. Here $X_L$ and $X_M$ represent mole fractions of $\text{L}$ and $\text{M}$, respectively, in the solution. The correct statement(s) applicable to this system is (are)

1. The point $\text{Z}$ represents vapour pressure of pure liquid $\text{M}$ and Raoult’s law is obeyed from $X_{L}0$ to $X_L=1$
2. The point $\text{Z}$ represents vapour pressure of pure liquid $\text{L}$ and Raoult’s law is obeyed when $x_{\to }L1$
3. The point $\text{Z}$ represents vapour pressure of pure liquid $\text{M}$ and Raoult’s law is obeyed when $x_L\to 0$
4. Attractive intermolecular interactions between $\text{L-L}$ in pure liquid $\text{L}$ and $\text{M-M}$ in pure liquid $\text{M}$ are stronger than those between $\text{L-M}$ when mixed in solution.

Q. 21.rate of reaction increases four times when the temperature changes from 300 Kelvin to 320 Kelvin. Calculate the energy of activation of reaction assuming that it does not change with temperature

Q. 1.4g of a sample of chalk containing clay as impurity were treated with excess of did hcl . Volume of co2 evolved when measured at 15^°c 768mm pressure was 282 cm .calculate the percentage purity of sample.

Q. $\Delta G^{0}vsT$ plot in the Ellinghm's diagram slopes downwards for the reaction

1. $Mg+\frac{1}{2}{O}_2\to MgO$
2. $2Ag+\frac{1}{2}{O}_2\to A{g}_{2}O$
3. $C+\frac{1}{2}{O}_2\to CO$
4. $CO+\frac{1}{2}{O}_2\to C{O}_2$

Q. Two liquids A and B form an ideal solution. At 300 K, the vapour pressure of a solution containing 1 mole of A and 3 mole of B is 550 mm of Hg. At the same temperature, if one more mole of B is added to this solution, the vapour pressure of the solution increases by 10 mm of Hg. Determine the vapour pressure of A and B in their pure states.

Q. At what temperature Celsius and Fahrenheit are equal?

1. $-{25}^{\circ }C$
2. $-{35}^{\circ }C$
3. $-{40}^{\circ }C$
4. $-{30}^{\circ }C$

Q. A $6\%$ glucose solution and $2\%$ solution of ‘x’ show same relative lowering of vapour pressure, assuming ‘x’ to ba a non-electrolyte, the molecular weight of ‘x’ is

1. 20
2. 30
3. 60
4. 50

Q. In the Elligham diagram, graph for the formation of $C{O}_2$ from $CO$

1. Is a straight line with negative slope
2. Is a straight line with positive slope
3. Is a straight line almost parallel to temprature axis
4. Is a curved line with sudden change in the slope

Q. The rate constant of a reaction at 300K and 280K respectively are K1 and K2 then

A)K1=20K2
B)K2=4K1
C)K1=4K2
D)K1=0.5K2