Some Basic Concepts in Chemistry – Interactive Quiz & Cheatsheet

Master the fundamentals of chemistry with this engaging quiz and quick-reference guide designed for Class 11 students

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Categories: Mini Game, Chemistry, Class 11, Physical Chemistry

Tags: Mini Game, Chemistry, Class 11, Some Basic Concepts, Mole Concept, Stoichiometry

Basic Chemistry Cheatsheet & Quiz

Mole: SI unit for amount of substance; contains \(6.022 \times 10^{23}\) particles (Avogadro's number).
Molar Mass: Mass of one mole in grams; \( \text{M} = \frac{\text{mass}}{\text{moles}} \).
Empirical Formula: Simplest whole-number ratio of atoms.
Molecular Formula: Actual number of atoms of each element in a molecule.
Stoichiometry: Use balanced equations to relate moles, mass, & volume.
Limiting Reagent: Reactant that runs out first, limits product formed.
Atomic Mass Unit (amu): \(1\,\text{amu} = 1/12\) mass of a carbon-12 atom.
Law of Conservation of Mass: Mass is neither created nor destroyed in chemical reactions.
Percentage Composition: \( \% = \frac{\text{mass of element}}{\text{total mass}} \times 100 \).
Avogadro's Law: Equal volumes of gases at same T and P contain equal number of molecules.

Term	Definition / Formula	Example / Note
Mole	\(1\,\text{mole} = 6.022 \times 10^{23}\) entities	1 mole of Na = \(6.022 \times 10^{23}\) atoms Na
Molar Mass	\(\text{M} = \frac{\text{mass (g)}}{\text{moles}}\)	Molar mass H\(_2\)O = 18.02g/mol
Empirical Formula	Simplest ratio (CH for C\(_6\)H\(_6\))	Benzene: empirical = CH, molecular = C\(_6\)H\(_6\)
Stoichiometry	Balanced equation gives mole ratios	\(2H_2 + O_2 \rightarrow 2H_2O\): 2:1:2 ratio
Limiting Reagent	Least moles consumed first	Calculates max possible product
Atomic Mass	\(\text{Relative mass compared to C-12}\)	C = 12.00 amu by definition
% Composition	\(\frac{\text{mass of element}}{\text{total mass}} \times 100\)	H in H\(_2\)O: (2/18)×100=11.1%

Step 1: Always check units: grams, moles, liters.

Step 2: For formulas, reduce to *empirical form* first.

Step 3: When calculating product, always identify the limiting reagent.

Step 4: Use Avogadro's number for particle conversions.

Step 5: Balance equations for stoichiometry before calculations.

Converting grams → moles: \( \text{n} = \frac{\text{mass}}{\text{molar mass}} \).
Empirical formula steps: Convert mass to moles, divide by smallest, round to nearest whole number.
Mole concept: Use Avogadro’s number whenever particles are asked.
Volume of gas at STP: \(1\,\text{mol} = 22.4\,\text{L}\) (for ideal gases at STP).
Limiting reagent: Compare mole ratios from balanced equation.

Test your speed with 5 chemistry questions! You have 30 seconds per question.