One mole of carbon atoms has a mass of 12 g. Determine the number of atoms present in this sample:
(Given: Mass of \(C^{12}\) is $1.9926\times {10}^{-23}$ $g$)

1.	$1.2\times {10}^{23}$	2.	$6.022\times {10}^{22}$
3.	$12\times {10}^{22}$	4.	$6.022\times {10}^{23}$

Which of the following has the greatest number of molecules?

1. 64 g SO₂ 

2. 44 g CO₂

3. 48 g O₃ 

4. 8 g H₂

Percentage of C, H & N in a compound is given as follows:
C=40%; H=13.33%; N=46.67%

The empirical formula of the compound will be:
1. $C{H}_{2}N$
2. $C_2{H}_{4}N$
3. $C{H}_{4}N$
4. $C{H}_{3}N$

Find the mole fraction of the solute in a one molal aqueous solution.

1. 0.027

2. 0.036

3. 0.018

4. 0.009

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. 90.0 kg

2. 540 kg

3. 180 kg

4. 270 kg

(Atomic mass: Al = 27)

How many moles of KMnO₄ are reduced by 1 mole of KI in an alkaline medium?

1. One

2. Two

3. Five

4. One-fifth

How many significant figures are present in the following numbers?

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

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:

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

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: