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NEET CHEMISTRYSome Basic Concepts of ChemistryMedium

Question

0.33% of iron (by weight) is present in hemoglobin (Molecular wt = 67200). The number of iron atom(s) in one molecule will be:

A

1

B

2

C

3

D

4

Step-by-Step Solution

  1. Identify the Principle: The mass percentage (w/ww/w) of a component in a solution (or compound) is defined as the mass of the component divided by the total mass multiplied by 100 [Class 12 Chemistry, Ch 1, Sec 1.2.1, Eq 1.1].
  2. Calculate Mass of Iron: Mass of Iron=Percentage×Molecular Weight100\text{Mass of Iron} = \frac{\text{Percentage} \times \text{Molecular Weight}}{100} Mass of Iron=0.33×67200100=221.76 u\text{Mass of Iron} = \frac{0.33 \times 67200}{100} = 221.76 \text{ u}
  3. Determine Number of Atoms: The atomic mass of Iron (Fe) is approximately 56 u56 \text{ u} (standard data). Number of atoms=Total Mass of IronAtomic Mass of Fe\text{Number of atoms} = \frac{\text{Total Mass of Iron}}{\text{Atomic Mass of Fe}} n=221.76563.96n = \frac{221.76}{56} \approx 3.96 Rounding to the nearest whole number, there are 4 iron atoms per hemoglobin molecule.

Exam Context & Concepts Covered

This question aligns with the NEET CHEMISTRY syllabus, specifically targeting concepts from Some Basic Concepts of Chemistry. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

CHEMISTRYSome Basic Concepts of Chemistryweightpresenthemoglobinmolecularnumber

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