Henry's Law

Q. $H_{2}S$ , a toxic gas with a rotten egg like smell is used for the qualitative analysis. If the solubility of $H_{2}S$ in the water at STP is $0.195m$, then Henry's law constant (in atm) is nearly :

1. 28.94
2. 285
3. 145.2
4. 2890.4

Q.

State henrys law and its applications.

Q.

What is a positive and negative deviation from Raoults law?

Q.

The oxygen dissolved in water exerts a partial pressure of 20 kPa in the vapour above water. The molar solubility of oxygen in water is $······\times {10}^{-5}\mathrm{mol}{\mathrm{dm}}^{-3}$(Round off to the Nearest Integer). Given: Henry’s law constant $={\mathrm{K}}_{\mathrm{H}}=8.0\times {10}^4\mathrm{kPa}$ for ${\mathrm{O}}_2$. The density of water with dissolved oxygen = $1.0\mathrm{kg}{\mathrm{dm}}^{-3}$

Q.

The partial pressure of ethane over a saturated solution containing 0.0656g of ethane is 1 bar. If the solution contains 0.0500g of ethane, then what should be the partial pressure of the gas?

1. 0.762 bar
   
2. 0.755 bar
   
3. 0.764 bar
   
4. 0.772 bar

Q.

Henrys law constant for the molality of methane in benzene at 298 K is 4.27×105 mm Hg. Calculate the solubility of methane in benzene at 298 K under 760 mm Hg.

Q. An aqueous solutionof glucose is made by dissolving 10g of glucose in 90g water at 303K. If the vapour pressure of pure water at 303K be 32.8mm Hg, what would be the vapour pressure of the solution?

Q. Consider the following statements:
Statement I:
The tanks used by scuba divers are filled with air diluted with helium.
Statement II:
For scuba divers , increased pressure increases the solubility of atmospheric gases in blood, thus more $N_2$ is dissolved in blood underwater at high pressure

1. Both the statements are correct.
2. Statement I is correct whereas statement II is incorrect
3. Statement I is incorrect whereas statement II is correct
4. Both the statements are incorrect.

Q.

QUESTION 2.39

The air is a mixture of a number of gases. The major components are oxygen and nitrogen with approximate proportion of $20\%$ is to $79\%$ by volume at 298 K. The water is in equilibrium with air at pressure of 10 atm. At 298 K if the Henry's law constants for oxygen and nitrogen at 298 K are $3.30\times {10}^{7}mm$ and $6.51\times {10}^{7}mm$ respectively, calculate the composition of these gases in water.

Q.

Value of Henrys constant ${\mathrm{K}}_{\mathrm{H}}$?

1. Increases with an increase in temperature

2. Decreases with increase in temperature

3. Remains constant

4. First increases then decreases

Q.

18 g of glucose is added to 178.2 g of water. The vapour pressure of water for this aqueous solution at 100º C is:

1. 7.60 Torr

2. 76.00 Torr

3. 752.40 Torr

4. 759.00 Torr

Q.

Mole fraction of component A in vapour phase is${\mathrm{x}}_1$​ and mole fraction of component A in liquid mixture is ${\mathrm{x}}_2$​, then, the total vapour pressure of liquid mixture is :

Q. Calculate the concentration of $C{O}_2$ in a soft drink that is bottled with a partial pressure of 4 atm over the liquid at ${25}^{\circ }C$. The Henry's law constant for $C{O}_2$ in water at ${25}^{\circ }C$ is $3.1\times {10}^{-2}atmmo{l}^{-1}L$

1. $0.129M$
2. $129.03M$
3. $0.224M$
4. $224.3M$

Q.

What is the significance of Henrys Law constant ${\mathrm{K}}_{\mathrm{H}}$?

Q.

How many millimoles of ${\mathrm{N}}_2$ gas would dissolve in 1 liter of water if ${\mathrm{N}}_2$ gas is bubbled through water at $293\mathrm{K},$ and exerts a partial pressure of$0.987\mathrm{bar}.$Given that Henry’s law constant for ${\mathrm{N}}_2$ at $293\mathrm{K}\mathrm{is}76.48\mathrm{kbar}$?

Q.

What is the application of Henry's law in deep sea diving?

Q. Which of the following mathematical expression correctly represents the Henry's law?
(Where $p$ is the partial pressure of gas over the solution, $K_H$ is Henry’s law constant and $\chi$ is mole fraction of the gas in the solution.)

1. $p^2\times \chi =K_H$
2. $p\times {\chi }^2=K_H$
3. $\chi =\frac{p}{K_H}$
   
4. None of the above

Q.

Question 42
(a) Explain the following phenomena with the help of Henry's Law.
(i) Painful condition known as bends.
(ii) Feeling of weakness and discomfort in breathing at high altitude.
(b) Why soda water bottle kept at room temperature fizzes on opening/

Q. For a dilute solution, Raoult’s law states that

1. The lowering of vapour pressure is equal to the mole fraction of the solute.
2. The relative lowering of vapour pressure is equal to the mole fraction of the solute
3. The vapour pressure of the solution is equal to the mole fraction of the solvent.
4. The relative lowering of vapour pressure is proportional to the amount of solute in the solution

Q. Assertion: $La(OH{)}_3$ is the most basic, while $Lu(OH{)}_3$ is the least basic.

Reason: As the size of lanthanoids decreases, covalent character of hydroxides decreases and basic character increases.

1. If both assertion and reason are true and reason is the correct explanation of assertion.
2. If both assertion and reason are false.
3. If both assertion and reason are true but reason is not the correct explanation of assertion.
4. If assertion is true but reason is false.

Q.

Question 01
Which of the following units is useful in relating concentration of solution with its vapour pressure?
(a) Mole fraction (b) Parts per million
(c) Mass percentage (d) Molality

Q. The Henry's Law constant for Helium, Hydrogen, Nitrogen and Oxygen at $293K$ are $144.97kBar,69.16kBar,76.48kBarand34.86kBar$ respectively.
Then which of the following gas will have the highest solubility in water at the given temperature of $293K$ and atmospheric pressure?

1. Helium
2. Hydrogen
3. Nitrogen
4. Oxygen

Q.

QUESTION 2.12

State Henry's law and mention some important applications?

Q.

The enthalpy of vapourisation of water is 186.5 KJ/mol, then what is it's entropy of vapourisation

Q. 139.18g OF GLUCOSE IS ADDED TO 178.2g OF WATER.THE VAPOUR PRESSURE OF WATER FOR THIS AQUEOUS SOLUTION AT 100^° c i

Q.

The system that forms maximum boiling azeotrope is

1. Carbon disulphide - Acetone

2. Benzene - Toluene

3. Acetone - Chloroform

4. n-hexane - n-heptane

Q.

Question 06
Low concentration of oxygen in the blood and tissues of people living at high altitude is due to..............
(a) low temperature
(b) low atmospheric pressure
(c) high atmospheric pressure
(d) Both low temperature and high atmospheric pressure

Q. A closed soda can has the concentration of ${\text{CO}}_2\text{at}{25}^{\circ }C$ equal to $0.408m$. Thus, the pressure of ${\text{CO}}_2$ gas in the can is $(K_H=0.034kgmo{l}^{-1}bar)$

1. $0.005bar$
2. $0.007bar$
3. $0.014bar$
4. $0.071bar$

Q. Which of the following will show a negative deviation from raoults law?
A. Acetone-benzene
B. Acetone-ethanol
C. Benzene- methanol
D. Acetone-chloroform

Q.

Why the solubility of gas in liquid decreases with increase in KH value at given pressure