Нужно рассчитать массовую долю элементов:

1. H2SO4

2. HNO3

3. H2CO3

4. KMnO4

5. K2C2O7

1) M (h2so4) = 98 г/моль

w (h) = (2/98) * 100=2.04%

w (s) = (32/98) * 100=32.65%

w (o) = (64/98) * 100=65.31%

2) M (HNO3) = 63 г/моль

w (h) = (1/63) * 100=1.59%

w (n) = (14/63) * 100=22.22%

w (o) = (48/63) * 100=76.2%

3) M (H2CO3) = 62 г/моль

w (h) = (2/62) * 100=3.23%

w (c) = (12/62) * 100=19.05%

w (o) = (48/62) * 100=77.42%

4) M (KMnO4) = 158 г/моль

w (K) = (39/158) * 100=24.96%

w (Mn) = (55/158) * 100=34.81%

w (o) = (64/158) * 100=40.51%

5) M (K2C2O7) = 214 г/моль

w (K) = (78/214) * 100=36.45%

w (c) = (24/214) * 100=11.215%

w (o) = (112/214) * 100=52.34%