AP Inter 1st Year Chemistry Answer Key 2025 with Exam Analysis (Available), Student Reviews

1. Which of the gases diffuses faster among N₂, O₂ and CH₁? Why?

The gas that diffuses faster among N₂, O₂, and CH₄ is CH₄ (methane). This is because the rate of diffusion of a gas is inversely proportional to the square root of its molecular weight. Methane has the lowest molecular weight among the three gases.

2. How many number of moles of glucose are present in 540 gms of glucose?

To find the number of moles of glucose present in 540 g of glucose, we need to know the molar mass of glucose. The molar mass of glucose (C₆H₁₂O₆) is 180 g/mol. We can calculate the number of moles as follows:

moles = mass / molar mass

moles = 540 g / 180 g/mol

moles = 3 mol

3. What are intensive and extensive properties?

Intensive properties are those that do not depend on the amount of substance present, such as temperature, pressure, and density. Extensive properties, on the other hand, depend on the amount of substance present, such as mass, volume, and energy.

4. What is the relationship between Cp and Cv?

The relationship between Cp (specific heat capacity at constant pressure) and Cv (specific heat capacity at constant volume) is given by the equation:

C _p = C _v + R

where R is the gas constant.

5. What is heterogenous equilibrium? Write two heterogeneous reactions.

Heterogeneous equilibrium refers to a state of equilibrium in a system where the reactants and products are in different phases, such as solid, liquid, or gas. Two examples of heterogeneous reactions are:

1. CaCO₃ (s) ⇌ CaO (s) + CO₂ (g)

2. Zn (s) + CuSO₄ (aq) ⇌ ZnSO₄ (aq) + Cu (s)

6. Why is gypsum added to cement?

7. Describe the important uses of caustic soda.

Caustic soda (sodium hydroxide) has several important uses, including:

• Production of paper and pulp
• Manufacture of soap and detergents
• Production of aluminum
• Water treatment and purification

8. What is Bio-Chemical Oxygen Demand (BOD)?

9. What is PAN? What effect is caused by it?

PAN (Peroxyacetyl Nitrate) is a pollutant that can cause damage to crops and vegetation. It is formed through the reaction of nitrogen oxides and volatile organic compounds in the atmosphere.

10. How do you prepare ethyl chloride from ethylene?

Ethyl chloride can be prepared from ethylene through the following reaction:

C₂H₄ + HCl → C₂H₅Cl

This reaction involves the addition of hydrogen chloride to ethylene in the presence of a catalyst

Overall difficulty level of the paper

Difficulty Level of Section A

Easy to Moderate

Difficulty Level of Section B

Moderate

Difficulty Level of Section C

Moderate

Expected Good Score

55 to 60

Time-Consuming Question (If any)

None

Topics with Maximum Weightage

• Caustic Soda
• Bio-Chemical Oxygen
• Ethyl Chloride
• Formation of Coordinate Covalent Bond
• Heavy Water
• Borax Bread Test
• S, P, D and F Block Elements