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

The volume of CO₂ obtained by the complete decomposition of 9.85 grams of BaCO3 is:

1. 2.24 lit.

2. 1.12 lit.

3. 0.84 lit.

4. 0.56 lit

The percentage of Se in peroxidase anhydrous enzyme is 0.5% by weight (at. wt = 78.4) then the minimum molecular weight of peroxidase anhydrous enzymes is:

1. $1.568$ $\times$ ${10}^4$

2. $1.568$ $\times$ ${10}^3$

3. 15.68

4. $2.136$ $\times$ ${10}^4$

The mass of carbon anode consumed (giving only carbon dioxide) in the production of 270 kg of aluminum metal from bauxite by the Hall process is:

1. 90 kg

2. 540 kg

3. 180 kg

4. 270 kg

(Atomic mass : Al = 27)