Question

4P+ 5O2 -> P4O10

Answer 1

If 4 moles of P is used by 5 mole of O2
then....0.489 moles will be used by 5/4 × .489 = .611 moles of O2

so .611 moles

so if 4 moles of P is burnt , 1 mole of P4O10 is produced ....so for .489 moles...... .489/4=.122 moles !
so mass will be .122× 283.89 = 34.7 grams

so first ans is .611 moles and second is 34.7 grams !

if you have any problem regarding this , just comment !!!

Answer 2

Hope this helps you.