Question

A substance contains 0.25% iron by weight. The molecular mass of the substance is 89600. The number of iron atoms per molecule of the substance is :

• A. 5
• B. 4
• C. 3
• D. 2

Answer 1

The correct option is B 4

The compound contains 0.25% Iron.

The molecular mass of the compound= 89600 g/mole.

Hence mass of Iron in the compound.

$=\frac{0.25}{100}\times 89600=224$g.

The atomic mass of Iron = 56g.

Hence, no. of iron atoms in the compound$=\frac{224}{56}=4$ atoms.

Hence option B is correct.