Mole Concept (11 Chemistry)
Master the mole as the central concept connecting atomic mass, molecular mass, and stoichiometry in chemistry.
TL;DR: Master the mole as the central concept connecting atomic mass, molecular mass, and stoichiometry in chemistry.
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Master the mole as the central concept connecting atomic mass, molecular mass, and stoichiometry in chemistry.
Mole Concept MCQs with Answers & Explanations
Q1. What is a mole?
- A small amount
- Unit of mass
- Avogadro number of particles ✓ (correct)
- One gram of substance
Q2. What is Avogadro's number?
- 6.02 × 10²³ ✓ (correct)
- 3.14
- 9.81
- 1.67 × 10⁻²⁷
Q3. What is molar mass?
- Half of atomic mass
- Mass of one mole of substance ✓ (correct)
- Number of particles
- Density of substance
Q4. How many moles are in 32 g of oxygen gas (O₂)? (Atomic mass of O = 16)
- 0.5 moles
- 1 mole ✓ (correct)
- 2 moles
- 32 moles
Q5. What is the relationship between moles, mass, and molar mass?
- Moles = mass + molar mass
- Moles = mass / molar mass ✓ (correct)
- Moles = mass × molar mass
- Moles = molar mass - mass
Q6. How many atoms are in 2 moles of carbon?
- 6.02 × 10²³
- 2 × 6.02 × 10²³ ✓ (correct)
- 3 × 6.02 × 10²³
- 0.5 × 6.02 × 10²³
Q7. What is the molar volume of a gas at STP?
- 11.2 L/mol
- 22.4 L/mol ✓ (correct)
- 44.8 L/mol
- 5.6 L/mol
Q8. What is molecular mass?
- Mass of one atom
- Sum of atomic masses in a molecule ✓ (correct)
- Mass of one mole
- Density of molecule
Q9. Calculate the number of molecules in 4.4 g of CO₂. (C = 12, O = 16)
- 6.02 × 10²³
- 0.5 × 6.02 × 10²³
- 2 × 6.02 × 10²³ ✓ (correct)
- 0.1 × 6.02 × 10²³
Q10. What is empirical formula?
- Actual formula of compound
- Simplest whole number ratio of atoms ✓ (correct)
- Number of atoms in molecule
- Molecular structure
Frequently Asked Questions
What is the difference between atomic mass unit and molar mass?
Atomic mass unit (u) is for individual atoms. Molar mass (g/mol) is for one mole of particles. Numerically they are equal but units differ.
How is the mole concept used in stoichiometry?
Stoichiometry uses mole ratios from balanced equations to calculate reactants needed and products formed in chemical reactions.
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