Molar Volume & Calculations Involving Gases at STP Solved | Class 11 Chemistry Unit 1 Stoichiometry

Calculation Involving Gases | Avogadro's Law, STP & Molar Volume (22.4 dm³) | Class 11 Chemistry Unit 1 Stoichiometry Learn how to calculate the volume of a gas at STP using moles and molar volume, with every formula and two fully solved examples (Ex 1.9 and Ex 1.10). In this lecture: ✅ Why we use the volume of gases in gaseous reactions ✅ Avogadro's Law – equal volumes of all gases at the same temperature and pressure contain an equal number of particles ✅ STP (Standard Temperature and Pressure) – 273 K / 0°C and 760 mm Hg / 1 atm ✅ 1 mole = 6.023 × 10²³ particles ✅ Molar Volume – the volume occupied by one mole of any gas: 22.4 dm³ at STP ✅ Formulas: Number of moles = Mass in g ÷ Molar mass, and Volume of gas = Molar volume × Number of moles ✅ Ex 1.9 – If 15 g of sulphur burns in oxygen, what volume of SO₂ is produced at STP? (Answer: 10.51 dm³) ✅ Ex 1.10 – What volume of chlorine gas is needed at STP to produce 10 dm³ of HCl gas? (Answer: 5 dm³ of Cl₂) Perfect for Class 11 (1st year / FSc Part 1) students preparing for exams. Everything is explained step by step with the full working, so you can solve any similar numerical on your own. If you get stuck on a question, write it in the comments and we'll help. 📌 Watch the full chapter in order: Unit 1 Stoichiometry playlist: [add playlist link] Next lecture: [add link] 👍 Like, comment and subscribe for more Class 11 Chemistry lectures. #Class11Chemistry #Stoichiometry #MolarVolume 📚 About Us: The Knowledge Academy Kohat provides complete lecture series for Class 8–12 covering Chemistry, Biology, Mathematics, Physics and more, helping students prepare for exams with clear, structured explanations.