Gas Laws

Step 1: Understanding the SI unit of pressure.
Pressure is defined as force per unit area. The SI unit of force is the newton (N), which is defined as: Pressure is thus measured in pascals (Pa), where: Step 2: Analyzing the options.
(A) kg ms : This is incorrect. This is the unit of force, not pressure.
(B) kg m : This is incorrect. This unit does not correspond to pressure.
(C) kg m s : This is correct. This is the SI unit for pressure, pascal (Pa).
(D) kg m s: This is incorrect. This is not the unit of pressure.
Step 3: Conclusion.
The correct answer is (C) kg m s .

Step 1: Understanding the reaction.
The reaction involves the hydrogenation of benzyl chloride using palladium on barium sulfate (Pd/BaSO ) to form benzaldehyde. In this reaction, the -CH Cl group is converted into -CHO, leading to the formation of benzoyl chloride (C H -COCl).
Step 2: Analyzing the options.
(A) Benzoic acid: This is incorrect. The product is benzoyl chloride, not benzoic acid.
(B) Benzyl chloride: This is incorrect. Benzyl chloride is the starting material, not the product.
(C) Benzoyl chloride: This is correct. The product of this reaction is benzoyl chloride.
(D) Chlorobenzene: This is incorrect. The reaction does not form chlorobenzene.
Step 3: Conclusion.
The correct answer is (C) Benzoyl chloride.

Step 1: Understanding the enthalpy of formation.
The reaction of ethanol formation involves the following steps: 1. The enthalpy of formation of ethanol from ethene and water involves subtracting the enthalpies of the combustion of ethanol and water. 2. Using Hess’s Law, we add or subtract the given reactions to get the formation enthalpy of ethanol.
Step 2: Analyzing the reactions and enthalpy values.
We have the following reactions: By combining the reactions appropriately (subtracting reaction i from reaction ii), we get the enthalpy of ethanol formation: Step 3: Conclusion.
The correct answer is (C) -42.0 kJ.

Step 1: Understanding liquefaction of gases.
Liquefaction of gases is easier for those with higher molecular weights and stronger intermolecular forces. These gases can be more easily condensed into a liquid phase.
Step 2: Analyzing the options.
(A) Oxygen: Oxygen is a relatively small molecule and does not liquefy easily under standard conditions.
(B) Helium: Helium is a noble gas and has very weak intermolecular forces, making it difficult to liquefy even at very low temperatures.
(C) Chlorine: Chlorine has a higher molecular weight and stronger intermolecular forces compared to oxygen and helium, making it more likely to liquefy.
(D) Nitrogen: Nitrogen also has weak intermolecular forces and liquefies under conditions similar to oxygen.
Step 3: Conclusion.
The correct answer is (C) Chlorine, as it liquefies more easily due to stronger intermolecular forces.

In this problem, we are told that the rate is proportional to the square of concentration of , and independent of the concentration of . Hence, the rate law is: where is the rate constant.

According to Henry’s law, the solubility of a gas ( ) in a liquid is directly proportional to the external pressure ( ) at a constant temperature.
Conclusion: The relationship is .

Step 1: Identify the process
The question asks for the oxidation potential ( ).
Given reduction potential , so .
Step 2: Nernst Equation
For oxidation :


Step 3: Calculation


Final Answer: (C)

Step 1: Concept
Highest value = Weakest base.
Step 2: Basicity Trend
- Aliphatic amines are more basic than ammonia. - Aromatic amines (like Aniline, ) are significantly weaker bases because the lone pair on Nitrogen is delocalized into the benzene ring. - (B) is Benzylamine, where the is not directly on the ring, so it is more basic than aniline.
Step 3: Conclusion
Aniline is the weakest base among the options, thus having the highest .
Final Answer: (C)

Step 1: Moles at STP
At STP, .
Moles in .
Step 2: Molecule Calculation
Molecules
Molecules
Step 3: Calculation

Final Answer: (D)

Step 1: Linkage Identification
The linkage is known as an amide (or peptide) linkage.
Step 2: Analysis
- (A) Glyptal is a polyester. - (B) Thermocol (Polystyrene) is an addition polymer of styrene. - (C) Buna-N is a copolymer of butadiene and acrylonitrile. - (D) Urea-formaldehyde resin is formed from Urea ( ) and Formaldehyde, maintaining the amide bond structure.
Final Answer: (D)

We can use Boyle's law to solve this problem, which states that for a constant temperature, the volume of a gas is inversely proportional to its pressure. The formula for Boyle’s law is: Where: - is the initial pressure, - is the initial volume, - is the final pressure, - is the final volume, which we need to find. Rearranging the formula to solve for : Substitute the known values: Thus, the volume of the gas at 2.0 atm pressure is .

Concept:
According to Zaitsev's rule, during elimination reactions, the more substituted alkene is formed as the major product because it is more stable. Step 1: Understand stability of alkenes. Alkene stability increases with substitution:
Step 2: Analyze options.

• (A) → least substituted
• (B) → di-substituted
• (C) → tri-substituted
• (D) → tetra-substituted (most stable) \checkmark

Step 3: Conclusion.

At standard temperature and pressure (STP), the molar volume of an ideal gas is always 22.4 L/mol. This is derived from the ideal gas law, where 1 mole of an ideal gas occupies 22.4 L at 0°C (273 K) and 1 atm pressure. Thus, the correct molar volume at STP is 22.4 L/mol, corresponding to option (1).

Step 1: Use the ideal gas law The ideal gas law is: where: - is the pressure (in atm), - is the volume (in liters), - is the number of moles of gas, - is the ideal gas constant ( ), - is the temperature (in Kelvin). Step 2: Substitute the given values Given: - Pressure , - Volume , - Temperature , - . Now, solve for : Substitute the known values: Answer: Therefore, the total number of moles of gas in the container is approximately . So, the correct answer is option (1).

Step 1: Use Boyle's Law to calculate the new volume Boyle’s law states that for a given amount of gas at constant temperature, the pressure and volume are inversely proportional: where: - and are the initial pressure and volume, - and are the final pressure and volume. Step 2: Substitute the given values Given: - Initial pressure , - Initial volume , - Final pressure , - Final volume is what we need to calculate. Substitute the values into Boyle’s law: Answer: Therefore, the volume of the gas at 1 atm pressure and 300 K temperature is . So, the correct answer is option (3).