ln a closed vessel, 50 ml of $A_2{B}_3$ completely reacts with 200 ml of C₂ according to the following equation:

$2A_2{B}_3\left(g\right)<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>5C_2\left(g\right)\to <mspace\; width="1em"></mspace>3C_3{B}_2\left(g\right)+C{A}_4\left(g\right)$

What will be the composition of the gaseous mixture in the system?

1. 100 ml $C_2,<mspace\; width="1em"></mspace>50<mspace\; width="1em"></mspace>ml<mspace\; width="1em"></mspace>C_3{B}_2,50<mspace\; width="1em"></mspace>ml<mspace\; width="1em"></mspace>C{A}_4$

2. 25 ml $C_2,<mspace\; width="1em"></mspace>75<mspace\; width="1em"></mspace>ml<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>C_3{B}_{\mathrm{2,}}<mspace\; width="1em"></mspace>25<mspace\; width="1em"></mspace>ml<mspace\; width="1em"></mspace>C{A}_4$

3. 75 ml $C_2,<mspace\; width="1em"></mspace>75<mspace\; width="1em"></mspace>ml<mspace\; width="1em"></mspace>C_3{B}_{2,<mspace\; width="1em"></mspace>}25<mspace\; width="1em"></mspace>ml<mspace\; width="1em"></mspace>C{A}_4$

4. 10 ml $C_2,<mspace\; width="1em"></mspace>25<mspace\; width="1em"></mspace>ml<mspace\; width="1em"></mspace>C_3{B}_{2,<mspace\; width="1em"></mspace>}100<mspace\; width="1em"></mspace>ml<mspace\; width="1em"></mspace>C{A}_4$

If the molar concentration of ${\mathrm{SnCl}}_4$ is $1.5$ $\times$ ${10}^{-3}$ mol L^–1, the concentration of chloride ions will be:

Which of the following could be the molecular formula of a compound if 44 g of it produces 88 g of CO₂ and 36 g of H₂O on complete combustion?

1.  ${\mathrm{C}}_4{\mathrm{H}}_6$ $$

2.  ${\mathrm{C}}_2{\mathrm{H}}_6\mathrm{O}$ $$

3.  ${\mathrm{C}}_2{\mathrm{H}}_4\mathrm{O}$

4.  ${\mathrm{C}}_3{\mathrm{H}}_6\mathrm{O}$

Which of the following contains the maximum number of atoms ?

Find the substance among the following that contains the same number of molecules as 16 g of dioxygen (O₂).

1. 16 g O${}_3$

2. 16 g SO${}_2$

3. 32 g SO${}_2$

4. All of the above

How many moles of H₂SO₄ are present in 2.5 L of a 0.2 M solution?

1. 0.25

2. 0.5

3. 0.75

4. 0.2

Which of the following statements is correct?

1. 1 mole of electrons weights 5.4 mg .
2. 1 mole of electrons weights 5.4 kg. 
3. 1 mole of electrons weights 0.54 mg. 
4. 1 mole of electrons has 1.6$\times {10}^{-19}$ C of charge.

Which of the following is the odd one with regard to mass?

1. 1 g atom of sulphur 

2. 0.5 moles of CO${}_2$ 

3. 1 mole of O${}_2$ 

4. 3 × 10 ²³ molecules of SO${}_2$

Calculate the mass of one molecule of the compound C₆₀H₁₂₂.

Calculate the mass percentage of sodium in a breakfast cereal containing 110 mg of sodium per 100 g of cereal.

1. 0.110%

2. 0.0110 %

3. 11.0%

4. 0.22 %