дано
m(CuSO4) = 32 g
m(NaOH) = 4 g
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m(Cu(OH)2)-?
M(CuSO4) = 160 g/mol
n(CuSO4) = m/M = 32 / 160 = 0.2 mol
M(NaOH) = 40 g/mol
n(NaOH) = m/M = 4 / 40 = 0.1 mol
n(CuSO4) > n(NaOH)
2n(NaOH) = n(Cu(OH)2)
n(Cu(OH)2) = 1/2 = 0.5 mol
M(Cu(OH)2) = 98 g/mol
m(Cu(OH)2) = n*M = 0.5 * 98 = 4.9 g
ответ 4.9 г