IIT JEE , AIEEE Forum - Chemistry , Physical Chemistry

deedee

d collapsed polythene bag of 30l capacity is partially blown up by d addition of 10l N2 at 0.965 atm at 298k

subsequently enough O2 is pumped into d bag so that at 298k n pressure of 0.99 atm d bag contains full 30l

final presssure of O2 in polythene bag at 298 k

is

A) .6687atm

b)1.2atm

c).82atm

d).39 atm

i m gttin it as b bt d correct ansewr is a

2)1g Mg in vapour phase absorbs 50kj of energy

if d first n second ionisation energies of Mg are 740 and 1450kj mol^-1 respectively

d no. of moles of Mg2+ present in d final mixture is

answer is 0.31g

deedee

yeah solly

gt d first one stupid me

d second one plez try

dev_22oct

given pressure of N₂ =10 litre temp of N₂=298k

for N₂ when the bag is fully expanded

volume of N₂ =30 litre at 298 k

P₁V₁=P₂V₂

.965X10=P₂X30

P_N2 in 30litre bag at 298k=.322atm

P=P_O2+P_N2

.990=PO2+.322

P_O2=.688 atm

dev_22oct

740 kj/mol is the fst ionization energy...

740kj/mol is required for 1mol =24 g

so for 1 g=740/24=30.8kj/mol...

so out of 50kj of energy 30.8kj is required to convert it to Mg+

now rest of the energy(19.2kj) is used to convert it to Mg2+

1450kj/mol =24g

for 1g

19.2kj/mol=24x19.2/1450=.31g