Question

1. Calculate the amount of each reactant required to produce 750 ml of carbon dioxide when two volumes of carbon monoxide combine with one volume of oxygen to produce two volumes of carbon dioxide.
   \[\ce{2CO + O2 -> 2CO2}\]
2. Calculate the volume occupied by 80 g of carbon dioxide at STP.
3. Calculate the number of molecules in 4.4 gm of CO₂. [Atomic mass of C = 12, O = 16]
4. State the law associated in question no. (a) above.

Answer 1

\[\ce{2CO + O2 -> 2CO2}\]

a. From the equation, the volume ratio is:

2 volumes CO : 1 volume O₂ ​: 2 volumes CO_2​

So, for 750 mL CO₂:

CO required = 750 mL

O₂ required = `750/2`

= 375 mL

b. Molar mass of CO₂:

12 + (2 × 16) = 44 g mol⁻¹

Number of moles (n) = `80/44`

= 1.818 mol

At STP, 1 mole of gas occupies 22.4 L.

V = 1.818 × 22.4

V = 40.7 L

c. Moles of CO₂ = `4.4/44`

= 0.1 mol

1 mole contains 6.022 × 10²³ molecules.

Number of molecules = 0.1 × 6.022 × 10²³

= 6.022 × 10²²