a)
m(р-ра) = 490 g
W(H2SO4) = 10%
m(осадка) - ?
m(H2SO4) = 0.1 * 490 = 49 g
N(H2SO4) = 49 / (1*2+32+16*4) = 49/98 = 0.5 моль
0.5 mol x mol
H2SO4 + BaCl2 → BaSO4 + 2HCl
1 mol 1 mol
1:0.5 = 1:x
x = 0.5
m(BaSO4) = 0.5 * (137+32+16*4) = 116.5 g
б) m(р-ра) = 490 g
W(H2SO4) = 5%
m(осадка) - ?
m(H2SO4) = 0.05 * 490 = 24.5 g
N(H2SO4) = 24.5 / (1*2+32+16*4) = 49/98 = 0.25 моль
0.25 mol x mol
H2SO4 + BaCl2 → BaSO4 + 2HCl
1 mol 1 mol
1:0.25 = 1:x
x = 0.25
m(BaSO4) = 0.25 * (137+32+16*4) = 0.25 * 233 = 58.25 g
в)
m(р-ра) = 490 g
W(H2SO4) = 15%
m(осадка) - ?
m(H2SO4) = 0.15 * 490 = 73.5 g
N(H2SO4) = 73.5 / (1*2+32+16*4) = 73.5/98 = 0.75 моль
0.75 mol x mol
H2SO4 + BaCl2 → BaSO4 + 2HCl
1 mol 1 mol
1:0.75 = 1:x
x = 0.75
m(BaSO4) = 0.75*233 = 174.75 g
г) m(р-ра) = 490 g
W(H2SO4) = 20%
m(осадка) - ?
m(H2SO4) = 0.2 * 490 = 98 g
N(H2SO4) = 98 / (1*2+32+16*4) = 98/98 = 1 моль
1 mol x mol
H2SO4 + BaCl2 → BaSO4 + 2HCl
1 mol 1 mol
x = 1
m(BaSO4) = 1*233 = 233 g