Some Basic Concepts of Chemistry — Class 11 Chemistry NCERT Solutions (Free)

Free step-by-step NCERT solutions for Class 11 Chemistry chapter "Some Basic Concepts of Chemistry" — 8 important questions with detailed answers for CBSE board exam preparation.

TL;DR: Free step-by-step NCERT solutions for Class 11 Chemistry chapter "Some Basic Concepts of Chemistry" — 8 important questions with detailed answers for…

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Key Questions Covered:

  1. Calculate the number of moles in 27 g of Al (Atomic mass of Al = 27 u).
  2. Calculate the mass of 3.2 mol of oxygen atoms. (Atomic mass of O = 16 u)
  3. Calculate the number of molecules in 11.2 L of CO2 at STP (Molar mass of CO2 …
  4. + 5 more questions in the full chapter

Solutions Summary:

Question Status
Calculate the number of moles in 27 g of Al (Atomic mass … ✓ Solved
Calculate the mass of 3.2 mol of oxygen atoms. (Atomic ma… ✓ Solved
Calculate the number of molecules in 11.2 L of CO2 at STP… ✓ Solved

Showing 3 of 8 questions

Q1: Calculate the number of moles in 27 g of Al (Atomic mass of Al = 27 u).

Number of moles = mass (g) / molar mass (g/mol) Given: mass = 27 g Molar mass of Al = 27 g/mol Number of moles = 27 g / 27 g/mol Number of moles = 1 mol Answer: 1 mole of Al is present in 27 g.

Q2: Calculate the mass of 3.2 mol of oxygen atoms. (Atomic mass of O = 16 u)

mass (g) = number of moles × molar mass (g/mol) Given: Number of moles = 3.2 mol Molar mass of O = 16 g/mol mass = 3.2 mol × 16 g/mol mass = 51.2 g Answer: The mass of 3.2 mol of oxygen atoms is 51.2 g.

Q3: Calculate the number of molecules in 11.2 L of CO2 at STP (Molar mass of CO2 = 44 g/mol).

Step 1: Find number of moles using molar volume at STP. At STP, 1 mole of gas = 22.4 L Number of moles = Volume (L) / Molar volume (L/mol) Number of moles = 11.2 L / 22.4 L/mol Number of moles = 0.5 mol Step 2: Find number of molecules. Number of molecules = number of moles × Avogadro's number Num...

Showing 3 of 8 questions. Visit the full page for complete solutions.