NEETChemistrySome Basic Concepts of Chemistry
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): 8.0 g of CH ₄ and 22.0 g of CO ₂ contain the same number of molecules. Reason (R): Both CH ₄ and CO ₂ are polyatomic gases with the same atomicity. In the light of the above statements, choose the most appropriate answer from the options given below:
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A)
- BBoth (A) and (R) are correct but (R) is not the correct explanation of (A)
- C(A) is not correct but (R) is correct
- D(A) is correct but (R) is not correct
Correct answer
D. (A) is correct but (R) is not correct
Step-by-step solution
Assertion (A): Number of moles of CH ₄ = Given mass Molar mass = 8.0 16 = 0.5 mol Number of moles of CO ₂ = 22.0 44 = 0.5 mol Since the number of moles is equal, the number of molecules is also equal. Thus, Assertion (A) is correct. Reason (R): Atomicity is the total number of atoms present in one molecule of a substance. Atomicity of CH ₄ = 1 ( C ) + 4 ( H ) = 5 Atomicity of CO ₂ = 1 ( C ) + 2 ( O ) = 3 The atomicity of the two gases is different. Thus, Reason (R) is not correct. Therefore, (A) is correct but (R)