1.
What is the formula of Henry's law?
Correct Answer
B. P ∝ C (or) P = kH.C
Explanation
Henry's law states that the pressure of a gas above a liquid is directly proportional to the concentration of the gas in the liquid. Mathematically, this can be represented as P ∝ C (or) P = kH.C, where P is the pressure of the gas, C is the concentration of the gas in the liquid, and kH is the proportionality constant. This formula shows the relationship between pressure and concentration according to Henry's law.
2.
When is Henry's law applicable?
Correct Answer
A. At a constant temperature
Explanation
Henry's law states that the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas above the liquid, at a constant temperature. This means that as the pressure of the gas increases, more gas molecules will dissolve in the liquid. However, Henry's law does not depend on the osmotic pressure, which is the pressure required to prevent the flow of solvent into a solution through a semipermeable membrane. Therefore, the correct answer is "at a constant temperature".
3.
What does kH denote in Henry's law?
Correct Answer
C. Henry’s law constant
Explanation
kH denotes Henry's law constant. This constant represents the proportionality between the concentration of a gas in a liquid and the partial pressure of that gas above the liquid. According to Henry's law, the concentration of a gas in a liquid is directly proportional to its partial pressure. Therefore, kH is used to calculate the concentration of a gas in a liquid based on its partial pressure, or vice versa.
4.
The value of Henry’s law constant of a gas is dependent on which factors?
Correct Answer
D. All of the above
Explanation
The value of Henry's law constant of a gas is dependent on the nature of the solvent, the nature of the gas, as well as temperature and pressure. The nature of the solvent affects the solubility of the gas, while the nature of the gas determines its ability to dissolve in the solvent. Temperature and pressure also play a crucial role in determining the solubility of the gas in the solvent. Therefore, all of these factors contribute to the value of Henry's law constant.
5.
The limitation(s) of Henry's law is/are:
Correct Answer
C. Both A and B
Explanation
The correct answer is "Both A and B". Henry's law is limited in two ways. Firstly, it does not work when gases are placed under high pressure. This is because at high pressures, the gas molecules are forced closer together, which can cause them to interact and deviate from the ideal behavior assumed by Henry's law. Secondly, Henry's law is only applicable when the system molecules are in an equilibrium state. This means that the system must be at a steady state where the rate of gas molecules entering and leaving the liquid phase is equal.
6.
According to Henry's law, the partial pressure of the gas (Pgas) is directly proportional to __________ of gas in the dissolved state.
Correct Answer
C. The mole fraction
Explanation
According to Henry's law, the partial pressure of a gas in a solution is directly proportional to the mole fraction of the gas in the dissolved state. This means that as the mole fraction of the gas increases, the partial pressure of the gas also increases. The mole fraction is a measure of the amount of a particular gas compared to the total amount of all gases in the solution. Therefore, the correct answer is "the mole fraction".
7.
What are some important applications of Henry's law?
Correct Answer
D. All of the above
Explanation
Henry's law states that the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas above the liquid. This law has various applications. In packing soda cans, Henry's law is utilized to determine the appropriate amount of carbon dioxide to be dissolved in the liquid to achieve the desired carbonation. In respiration, Henry's law explains how oxygen is absorbed from the air into the bloodstream. In the production of carbonated beverages, Henry's law is used to control the amount of carbon dioxide dissolved in the beverage. Therefore, all of the given applications are important uses of Henry's law.
8.
What is the solubility of gaseous oxygen in water at a temperature of 293 K when the partial pressure exerted by O2 is 1 bar? (Given: kH for O2 34840 bar.L.mol-1)
Correct Answer
D. 2.87*10-5 M
Explanation
The solubility of gaseous oxygen in water at a temperature of 293 K when the partial pressure exerted by O2 is 1 bar is 2.87*10-5 M. This is determined using Henry's Law, which states that the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas above the liquid. The proportionality constant, known as the Henry's Law constant (kH), is given as 34840 bar.L.mol-1 for O2. By substituting the given values into the equation, we can calculate the solubility of O2 in water.
9.
Which gases do not obey Henry’s law?
Correct Answer
D. All of the above
Explanation
Henry's law states that the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas above the liquid. However, NH3 (ammonia), CO2 (carbon dioxide), and HCl (hydrochloric acid) do not obey Henry's law. These gases exhibit deviations from the ideal behavior due to factors such as hydrogen bonding, ionization, or molecular interactions. Therefore, the correct answer is "All of the above" as all the mentioned gases do not follow Henry's law.
10.
What is the unit of Henry's Law constant?
Correct Answer
C. Mol L–1 bar–1
Explanation
The unit of Henry's Law constant is mol L-1 bar-1.