Element ‘A’ reacts with oxygen to form a compound A2O3. If 0.359 gram of a compound contains 0.128 gram of oxygen, atomic weight of A will be ____? (assuming law of constant proportions is true).

0.359 gram of A2O3 contain 0.128 gram of oxygen  Then 3×16 gram of oxygen is present in 16×3×0.3590.128 gram  of A2O3=134.625 gram of A2O3 Total mass of ' A ' in A2O3=134.625-48=86.625 Therefore atomic mass of A=86.6252=43.3amuAllowed value = 43 to 43.5