Question

Oksidasinya cr di cr(no3)3 sama cr2(s04)2 sama biloknya besi belerang ama oksigen di fe2(so4)3

Answer 1

Cr(NO3)3
biloks NO3=-1
Cr + 3(NO3) = 0 <--- 0 karena muatan senyawa netral
Cr + 3(-1) = 0 
Cr + (-3) = 0
Cr = +3

Cr2(SO4)2
biloks SO4 = -2
2(Cr) + 2(SO4) = 0
2(Cr) + 2(-2) = 0
2(Cr) + (-4) = 0
2(Cr) = +4
Cr = +2

Fe2(SO4)3
biloks SO4 = -2
2(Fe) + 3(SO4) = 0
2(Fe) + 3(-2) = 0
2(Fe) + (-6) = 0
2(Fe) = +6
Fe = +3

Answer 2

Cr di Cr(NO3)3 = +3
Cr2(SO4)2 ini soalnya kurang bener ?
Fe = +3
S = +6
O = -2