Paragraph: The process of eudiometry is used to calculate the volume of the various reacting gases present together in a closed vessel, it is done by sparking the content and noting the volume change or pressure change depending upon the conditions mentioned. Various reagents like alkaline pyrogallol, turpentine oil, caustic potash, conc. H ₂ SO ₄ are used to absorb the selective gases like O ₂, O ₃, CO ₂ and H ₂ O (

Step-by-step solution

Let the no. of moles of H ₂, O ₂ and He are x , y and z respectively x+y+z=2.0 Pressure exerted by 2 moles of gaseous mixture is 50 atm . After the first electric spark decrease in pressure =50-12.5=37.5 ~atm decrease in no. of moles of gaseous mixture is 1.5 But from the given information limiting reagent in first step is O ₂ from H ₂( ~g )+ 1 2 O ₂( ~g ) H ₂ O ( ) H ₂ and O ₂ reacted are in the ratio of 2: 1 0.5 mole of O ₂ should be reacted with 1.0 mole of H ₂ No. of mole of O ₂ in the mixture ( y )=0.5 When ag