AP Inter 1st Year Chemistry Important Questions 2026-27, Download PDF Link

Covering the AP Inter 1st Year Chemistry syllabus requires regular revision of concepts, formulas, reactions and numerical applications. With multiple chapters and different types of questions to prepare, it can be challenging to identify the topics that need more attention and revise them effectively before the examination. Solving questions without understanding the underlying concepts can also make it difficult to apply the same principles to unfamiliar problems.

AP Inter 1st Year Chemistry Important Questions 2026-27 bring together key questions from the available reference material to support focused revision. Practise them chapter-wise, understand the concepts behind each answer and revise important formulas, reactions and numerical methods. Also use the latest syllabus, exam pattern and previous year questions alongside your preparation.

AP Inter 1st Year Chemistry Important Questions 2026-27

The following are important questions from the provided reference material, covering Some Basic Concepts in Chemistry, Structure of Atom and Classification of Elements. These include MCQs, numerical-based questions, formula-based questions and short-answer questions for focused revision.

Q1. Chemical equation is balanced according to the law of:

• A) Multiple proportions

• B) Reciprocal proportions

• C) Conservation of mass

• D) Definite proportion

Answer: C) Conservation of mass

Q2. Which of the following contains the greatest number of molecules?

• A) 448 L of O₂ at STP

• B) 440 L of CO₂

• C) 22.4 L of water at STP

• D) 2.24 L of H₂ at STP

Answer: A) 448 L of O₂ at STP

Q3. The empirical formula of an organic compound is CH₂. If the mass of 1 mole of the compound is 42 g, its molecular formula is:

• A) C₄H₈

• B) C₂H₄

• C) C₃H₆

• D) CH₂

Answer: C) C₃H₆

Q4. The number of moles of NaOH required to prepare a 0.2 M solution of 1 litre is:

• A) 0.2

• B) 0.5

• C) 4

• D) 2

Answer: A) 0.2 mol

Q5. Fill in the blanks / state the correct values:

1. One amu is numerically equal to 1.66 × 10⁻²⁴ g.

2. The numerical value of Avogadro constant is 6.023 × 10²³.

3. The number of atoms present in 64 g of S₈ is 2Nₐ = 1.204 × 10²⁴.

4. When 20 g of sugar (C₁₂H₂₂O₁₁) is dissolved in water to make a final volume of 2 L, the molarity of the solution is approximately 0.0292 M.

Q6. How many litres are present in 1 mL?

Answer: 0.001 L

Q7. In the reaction NaOH + H₂SO₄ → NaHSO₄ + H₂O, what is the equivalent weight of H₂SO₄?

Answer: 98

Calculation:

Equivalent weight = Molar mass / n-factor

For this reaction, the n-factor of H₂SO₄ is 1.

Therefore:

Equivalent weight = 98 / 1 = 98

Q8. Write the relation between the Kelvin scale and Celsius scale of temperature.

Answer:

K = °C + 273.15

For school-level calculations, K = °C + 273 may also be used.

Q9. How many molecules are present in 1 cc of N₂ gas at STP?

Answer: 2.69 × 10¹⁹ molecules

At STP, 22,400 cm³ of gas contains approximately 6.022 × 10²³ molecules.

Therefore, the number of molecules in 1 cm³ is approximately:

6.022 × 10²³ / 22,400 = 2.69 × 10¹⁹ molecules

Q10. The increasing order of the values of e/m for electron (e), proton (p), neutron (n) and α-particles is:

• A) e < p < n < α

• B) n < α < p < e

• C) n < p < e < α

• D) n < p < α < e

Answer: B) n < α < p < e

Q11. Thomson's model of the atom is also called:

• A) Plum pudding model

• B) Raisin pudding model

• C) Watermelon model

• D) All of the above

Answer: D) All of the above

Q12. Which electronic transition in the hydrogen atom requires the highest energy?

• A) n = 4 to n = 5

• B) n = 1 to n = 2

• C) n = 3 to n = 5

• D) n = 2 to n = 3

Answer: B) n = 1 to n = 2

Q13. The value of the Rydberg constant is:

• A) 109777 cm⁻¹

• B) 109977 cm⁻¹

• C) 109677 cm⁻¹

• D) 109277 cm⁻¹

Answer: C) 109677 cm⁻¹

Q14. The maximum number of electrons possible with spin quantum number +1/2 for principal quantum number n = 4 is:

• A) 16

• B) 9

• C) 4

• D) 25

Answer: A) 16

For n = 4, the maximum number of electrons is:

2n² = 2 × 4² = 32

Half of these electrons can have spin +1/2, giving 16 electrons.

Q15. Which of the following oxides forms an acidic solution when dissolved in water?

• A) Na₂O

• B) CO

• C) Al₂O₃

• D) Cl₂O₇

Answer: D) Cl₂O₇

Cl₂O₇ reacts with water to form perchloric acid (HClO₄), making the resulting solution acidic.

Q16. Which of the following shows the elements arranged in decreasing order of metallic character?

• A) Na > Mg > Be > Si > P

• B) P > Si > Be > Mg > Na

• C) Si > P > Be > Na > Mg

• D) Be > Na > Mg > Si > P

Answer: A) Na > Mg > Be > Si > P

Metallic character generally decreases from left to right across a period and increases down a group.

Q17. The atomic number of the element unnilennium is:

• A) 102

• B) 109

• C) 101

• D) 110

Answer: 109

The systematic temporary name “unnilennium” corresponds to atomic number 109.

AP Inter 1st Year Chemistry Chapter-Wise Important Questions

The questions can be grouped by topic to make chapter-wise revision more focused. Each topic below highlights two questions from the provided reference material.

Some Basic Concepts in Chemistry

Structure of Atom

Classification of Elements

 Before starting chapter-wise revision, check the AP Intermediate 1st Year syllabus coverage to make sure you are preparing the required Chemistry topics for the academic session.

AP Inter 1st Year Chemistry 2-Mark Important Questions

Short-answer preparation should focus on definitions, formulae, basic calculations and direct conceptual questions. From the provided material, important areas include:

• State the law according to which chemical equations are balanced.

• Write the relation between Kelvin and Celsius scales.

• Convert 1 mL into litres.

• State the value of Avogadro constant.

• Define or calculate equivalent weight.

• State the value of the Rydberg constant.

• Find the number of electrons with a given spin for a specified principal quantum number.

For the latest syllabus coverage, refer to the AP Inter 1st Year Syllabus 2027 while planning your revision.

AP Inter 1st Year Chemistry 4-Mark Important Questions

For questions requiring calculations or brief explanations, practise the following areas:

• Calculation of molecular formula from empirical formula and molar mass.

• Calculation of molarity from the given mass, volume and molar mass.

• Calculation of equivalent weight using the n-factor.

• Calculation of molecules present in a given volume of gas at STP.

• Calculation of maximum electrons for a given principal quantum number and spin.

• Explanation of periodic trends such as metallic character.

Check the AP Inter 1st Year Exam Pattern 2027 to understand the question paper format and marks distribution before planning your practice.

AP Inter 1st Year Chemistry 8-Mark Important Questions

For longer-answer preparation, focus on concepts that require explanation along with calculations or supporting examples. Important areas from the provided questions include:

• Mole concept and its applications in chemical calculations.

• Atomic models and their associated terminology.

• Electronic transitions and energy changes in hydrogen.

• Quantum numbers and electronic distribution.

• Periodic trends and variation in metallic character.

• Nature of oxides and their reactions with water.

The exact distribution of questions by marks should be checked against the latest AP Intermediate 1st Year Chemistry examination pattern before finalising your revision plan.

AP Inter 1st Year Chemistry Important Questions PDF

Keeping important Chemistry questions in one place makes revision more organised and supports repeated practice of key concepts. The table below can include the relevant question PDFs with clear titles and download options.

AP Inter 1st Year Chemistry Important Reactions

Reactions linked to important concepts should be revised along with the conditions and principles involved.

• Neutralisation and Acid Salts

NaOH + H₂SO₄ → NaHSO₄ + H₂O

This reaction is relevant to the calculation of the equivalent weight of H₂SO₄ because only one hydrogen ion is replaced in the formation of NaHSO₄.

• Formation of Perchloric Acid

Cl₂O₇ + H₂O → 2HClO₄

This reaction explains why Cl₂O₇ forms an acidic solution when dissolved in water.

AP Inter 1st Year Chemistry Important Numericals

The following numerical questions are based on the provided reference material. Practise each question by identifying the given values, selecting the appropriate formula and showing the calculation step by step.

Tip: While practising these numericals, write the formula first, substitute the given values and then state the final answer with the correct unit.

AP Inter 1st Year Chemistry Important Concepts and Definitions

Revise the key Chemistry concepts and definitions from each chapter to strengthen your understanding of important terms, principles and formulas before the AP Inter 1st Year examination.

AP Inter 1st Year Chemistry Previous Year Questions

Previous year questions help you understand how Chemistry concepts are asked in the examination and what types of questions you may need to practise. Along with the important questions above, solve questions from earlier AP Intermediate examinations and compare them with the latest syllabus and examination pattern.

Make sure to include AP Inter 1st Year PYQs in your revision routine. Solving these questions regularly can help you practise exam-style questions, identify topics that need more revision and become familiar with the question format.

How to Prepare AP Inter 1st Year Chemistry Important Questions?

Use the important questions as a revision tool rather than studying answers in isolation.

• Revise chapter-wise: Complete one chapter and its important concepts before moving to the next.

• Practise numericals: Solve mole concept, molarity, equivalent weight and gas-volume questions step by step.

• Learn important formulae: Keep formulas such as 2n², molarity and equivalent weight readily available during revision.

• Understand concepts: Focus on why an answer is correct, particularly for periodic trends and atomic structure.

• Practise objective questions: Solve MCQs after revising each topic to improve recall.

• Use previous papers: Compare important questions with previous year papers to understand recurring concepts and question formats.

• Revise before the examination: Revisit formulas, definitions, reactions and numerical methods during the final revision.

• Plan your revision around the exam: Check the AP Inter Time Table 2027 and divide your revision time between concepts, numericals, reactions and previous year questions.

AP Inter 1st Year Chemistry preparation should combine concept revision, numerical practice, important reactions and previous year questions. Start with the chapter-wise questions, understand the principles behind each answer and regularly revise formulas and key definitions. Use the latest syllabus and examination pattern alongside these questions to keep your preparation aligned with the 2026-27 academic session.