Дано
m(ppa H2SO4) = 196 g
W(H2SO4) = 10%
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m(Al(OH)3)-?
m(H2SO4) = 196*10% / 100% = 19,6 g
2AL(OH)3+3H2SO4-->Al2(SO4)3+6H2O
M(H2SO4) = 98n g/mol
n(H2SO4) = m/M =19.6 /98 = 0.2 mol
n(Al(OH)3) = 3n(H2SO4)
n(H2SO4) = 0.2 / 3 = 0.066 mol
M(Al(OH)3) = 78 g/mol
m(Al(OH)3) = n*M = 0.066 * 78 = 5.15 г
ответ 5.15 g