This is only true for the titration of a strong acid with a strong base or vice versa. At the equivalence point of the titration of a weak base with a strong acid the pH is less than 7.00 and at the equivalence point of the titration of a weak acid with a strong base the pH is greater than 7.00.
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 !!!
Mass is never lost or gained in chemical reactions. We say that mass is always conserved. In other words, the total mass of products at the end of the reaction is equal to the total mass of the reactants at the beginning. This is because no atoms are created or destroyed during chemical reactions.
