A hemoglobin molecule has a molecular weight of 67,200g/mol and contains 0.33% iron (Fe) by weight. Calculate the total number of iron atoms present in a single molecule of hemoglobin:

1.	1	2.	2
3.	3	4.	4

$4N{H}_3$ $+$ $5O_2$ $\to$ $6H_{2}O$ $+$ $4NO$

When 1 mole of ammonia (NH₃) reacts with 1 mole of oxygen (O₂), which of the following outcomes occurs regarding the consumption of the reactants?

The mole ratio of H₂ and O₂ gas is 8:1. The ratio of their weight will be:

A compound is composed of carbon, hydrogen, and oxygen. The percentage composition by mass is 40% carbon and 6.67% hydrogen, with the remaining percentage being oxygen. Determine the empirical formula of the compound:

1. $C{H}_{2}O$

2. $C{H}_{4}O$

3. $C{H}_4{O}_2$

4. $C{H}_{\mathrm{}}O$

The maximum number of molecules is present in:

Which of the following options incorrectly describes the possible range of values for the mole fraction (x) of a component in a mixture?

1. x < 1
2. – 2 ≤ x ≤ 2
3. 0 ≤ x ≤ 1
4. x is always non-negative

Determine the volume of CO₂ obtained by complete decomposition of 9.85 g of BaCO₃

1. 2.24 lit.

2. 1.12 lit.

3. 0.84 lit.

4. 0.56 lit

1 M, 2.5 litre NaOH solution is mixed with another 0.5 M and 3 litre NaOH solution. The molarity of the resultant solution will be:

Which among the following has the maximum number of molecules?

1. 7 gm N₂

2. 2 gm H₂

3. 16 gm NO₂

4. 16 gm O₂

The percentages of C, H, and N in an organic compound are 40%, 13.3%, and 46.7% respectively.
The empirical formula of the compound is: