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  1. Class 9
  2. Chapter 3 Class 9 - Atoms And Molecules (Term 2)

Transcript

Example 3.3 Calculate the number of moles for the following: (i) 52 g of He (finding mole from mass) Atomic mass of He = 4 u Molar mass of He = 4g Thus, Number of moles = (𝐺𝑖𝑣𝑒𝑛 π‘€π‘Žπ‘ π‘ )/(π‘€π‘œπ‘™π‘Žπ‘Ÿ π‘€π‘Žπ‘ π‘ ) = 52/4 = 13 Example 3.3 Calculate the number of moles for the following: (ii) 12.044 Γ— 1023 number of He atoms (finding mole from number of particles). Now, Number of moles = (𝐺𝑖𝑣𝑒𝑛 π‘€π‘’π‘šπ‘π‘’π‘Ÿ π‘œπ‘“ π‘ƒπ‘Žπ‘Ÿπ‘‘π‘–π‘π‘™π‘’π‘ )/(π΄π‘£π‘œπ‘”π‘Žπ‘‘π‘Ÿπ‘œ π‘π‘’π‘šπ‘π‘’π‘Ÿ) = (12.044 Γ—10^23)/(6.022 Γ— 10^23 ) = 2

Class 9
Chapter 3 Class 9 - Atoms And Molecules (Term 2)

About the Author

CA Maninder Singh's photo - Founder at Teachoo
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo