The Direction Academy Rind Jada

02/09/2026

Alhamdulillah

17/06/2026

*1ST YEAR CHEMISTRY*
*IMPORTANT SHORT* *QUESTIONS*

🔹*CHAPTER 1: STOICHIOMETRY*
▪︎Define Stoichiometry. What are its two basic assumptions?
▪︎Why does actual yield often turn out to be less than theoretical yield? Give three practical reasons.
▪︎How do you identify a limiting reactant in a chemical reaction?
▪︎Define molar volume. Why does 22.414 dm3 of different ideal gases contain the same number of molecules but have different masses?
▪︎Differentiate between a mole and Avogadro's number.
▪︎What is percentage yield? How does it help gauge the efficiency of a chemical process?
🔹*CHAPTER 2: ATOMIC STRUCTURE*

▪︎State and explain Hund's Rule using the electronic configuration of Nitrogen (N, Z=7).
▪︎Why is the (n+l) rule used to distribute electrons across subshells? Give an example comparing 4s and 3d.
▪︎State Heisenberg's Uncertainty Principle. Why is it irrelevant for macroscopic objects like a tennis ball?
▪︎Differentiate between Continuous Spectrum and Line Spectrum. Why is an atomic spectrum considered a fingerprint of an element?
▪︎What are Quantum Numbers? Briefly explain the significance of the Azimuthal Quantum Number (l).
▪︎Why do cathode rays cast a sharp shadow of an opaque object placed in their path?
🔹*CHAPTER 3: PERIODIC TABLE & PERIODIC PROPERTIES*

▪︎Why is the second ionization energy of an element always significantly greater than its first?
▪︎Define shielding effect. How does it explain the decreasing trend of ionization energy down a group?
▪︎Why is the electron affinity of Fluorine unexpectedly lower than that of Chlorine, despite its higher electronegativity?
▪︎Explain why atomic radius decreases across a period even though the number of shells remains the same.
▪︎How does metallic character vary across a period and down a group? Provide a conceptual reason.
▪︎Why do melting and boiling points of elements peak at Group IV-A (Group 14) and then drop off sharply?
🔹*CHAPTER 4: CHEMICAL BONDING*

▪︎Why does the He2 molecule not exist according

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