Question

The mass of P4O10 that will be obtained from the reaction of 1.33 gram of P4 and 5.07 of oxygen is

Answer 1

according to law of conservation of mass,
the mass should be equal, before and after reaction.
the mass obtained = 1.33+5.07 =6.40 grams

Answer 2

The mass of P4O10 that will be obtained from the reaction of 1.33 gram of P4 and 5.07 of oxygen is 3.05 gram