Mr(H2CO3) = Mr = 2Ar(H) + Ar(C) + 3Ar(O) = 2 * 1 + 12 + 3 * 16 = 62
w(H) = 2Ar(H) / Mr = 2 / 62 = 0.0323 = 3.23%
w(C) = Ar(C) / Mr = 12 / 62 = 0.1935 = 19.35%
w(O) = 3Ar(O) / Mr = 48 / 62 = 0.7742 = 77.42%
Mr(H2CO3) = Mr = 2Ar(H) + Ar(C) + 3Ar(O) = 2 * 1 + 12 + 3 * 16 = 62
w(H) = 2Ar(H) / Mr = 2 / 62 = 0.0323 = 3.23%
w(C) = Ar(C) / Mr = 12 / 62 = 0.1935 = 19.35%
w(O) = 3Ar(O) / Mr = 48 / 62 = 0.7742 = 77.42%