NEETChemistrySome Basic Concepts of Chemistry
What is the total number of electrons present in 1.6 g of methane ( CH ₄ )? (Given: Atomic masses of C = 12 u , H = 1 u ; N_A = 6.022 10²³ mol ⁻¹ )
Options
- A6.022 10²²
- B4.817 10²³
- C6.022 10²³
- D9.635 10²⁴
Correct answer
C. 6.022 10²³
Step-by-step solution
Molar mass of CH ₄ = 12 + 4 1 = 16 g mol ⁻¹ . Number of moles of CH ₄ = 1.6 g 16 g mol ⁻¹ = 0.1 mol . Number of CH ₄ molecules = 0.1 N_A = 0.1 6.022 10²³ = 6.022 10²² . One molecule of CH ₄ contains 6 electrons from carbon and 1 electron from each of the 4 hydrogen atoms, giving a total of 6 + 4 = 10 electrons. Total number of electrons = 10 6.022 10²² = 6.022 10²³ . Answer: 6.022 10²³