Question

How many number of moles in co2 contain 8.0g of oxygen?

Answer 1

Mass of Oxygen = 8 g
Molar mass of Oxygen =32g mol ⁻¹
Number of moles of Oxygen = 8 / 32 moles
                                              = 0.25 moles

1 mole of CO₂ will contain 1 mole of Oxygen
∴ 0.25 mole of oxygen is present in 0.25 moles of CO₂

Answer 2

Given:
Given weight Of O2= 8g
Molar mass of O2= 32g
Number of moles of Oxygen=
Given weight/molar mass
= 8/32
= 0.25 moles of O2
1mole of CO2 contains 1 mole of oxygen.
so
1mole of O2 -------> 1 mole of CO2
0.25 mole of O2---->?
=0.25 moles of CO2
∴0.25 moles of oxygen is present in 0.25 moles of CO2.