4.41
а)
2KMnO4 = K2MnO4 + MnO2 + O2
M(KMnO4) = 39 + 55 + 64 = 158
n(KMnO4) = 395/158 = 2.5
2.5/2 = x/1
x = 2.5 / 2 = 1.25
V(O2) = 1.25 * 22.4 = 28 л
б) реакцию выше см.
n(KMnO4) = 100/158 = 0.633
n(O2) = 0.633/2 = 0.3165
V(O2) = 0.3165 * 22.4 = 7.0896 = 7 л
в) n(KMnO4) = a/158
n(O2) = a/316
V(O2) = 22.4a/316 = 0.07a
4.45.
а)
2KClO3 = 2KCl + 3O2
n(O2)= 3
n(KClO3) = (2*3)/3 = 2
M(KClO3) = 39 + 35.5 + 48 = 122.5
m(KClO3) = 122.5 * 2 = 245 г
б) m(O2) = 40
M(O2) = 32
n(O2) = 40/32 = 1.25
n(KClO3) = (2*1.25)/3 = 0.8333
m(KClO3) = 122.5 * 0.8333 = 102 г
в) n(O2) = 16.8/22.4 = 0.75
n(KClO3) = (2 * 0.75)/3 = 0.5
m(KClO3) = 122.5 * 0.5 = 61.25 г
г) n(O2) = a/22.4
n(KClO3) = 2a/67.2
m(KClO3) = (122.5 * 2a)/67.2 = 245a/67.2 = 3.65a