Сделайте цепочку превращений k2so4-koh-khs-k2s-kno3-koh-k-kci

k2so4+ba(oh)2=baso4+2koh

koh+h2s=h2o+khs

khs+koh=k2s+h2o

k2s+2agno3=ag2s+2kno3

2kno3+ba(oh)2=ba(no3)2+2koh

4koh=4k+o2+2h2o

2k+cl2=2kcl

cu

4al + 3o2 = 2al2o3

2al + 3br2 = 2albr3

2al + n2 = 2aln

4al + p4 = 4alp