ПОМОГИТЕ РАССЧИТАТЬ МАСCОВЫЕ ДОЛИ ЭЛЕМЕНТОВ В ЭТИХ ВЕЩЕСТВАХ:
1) С6H6
2)NA2CO3
3)K2HPO4

1) w(C) = 72/78 *100 = 92%

w(H) = 100-92 = 8%

2) w(Na) = 46/106 * 100 = 43%

w(C) = 12/106 * 100 = 11%

w(O) = 100-43-11 = 46%

3) w(K) = 78/174 * 100 = 44,8%

w(P) = 31/174 * 100 = 17,8%

w(O) = 64/174 * 100 = 36,8%

w(H) = 100-44,8-17,8-36,8 = 0,6%