1)
дано
m1(ppa kcl) = 120 g
w1(kcl) = 15%
+m(kcl) = 20 g
w2(
m1(kcl) = 120*15% / 100% = 18 g
m( общ kcl) = m1(kcl) + m(kcl) = 18+20 = 38 g
m( общ ppa kcl) = 120 + 20 = 140 g
w2(kcl) = m( общ kcl) / m( общ ppa kcl) * 100% = 38 / 140 * 100% = 27.14%
ответ 27.14%
2)
дано
m(ppa naoh) = 56 g
w(naoh) = 5%
+al(no3)3
m(al(oh)
m(naoh) = 56*5% / 100% = 2.8 g
3naoh+al(no3)3--> 3nano3+al(oh)3
m(naoh) = 40 g/mol
n(naoh) = m/m = 2.8 / 40 = 0.07 mol
3n(naoh) = n(al(oh)3)
n(al(oh)3) = 0.07 / 3 = 0.023 mol
m(al(oh)3) = n*m = 0.023 * 78 = 1.82 g
ответ 1.82 г
a) 1. SiO2+ 2H2= Si+ 2H2O
2. 2Ca+ Si=(t)= Ca2Si
3.Ca2Si + 3H2= 2CaH2+ SiH4
4. SiH4+ 2O2= SiO2 + 2H2O
5. SiO2+ 2H2= Si + 2H2O
б) Si+ O2= SiO2
2. SiO2 + Na2O= Na2SiO3
3. Na2SiO3 + H2SO4= H2SiO3+ H2SO4
4. H2SiO3= H2O + SO2
5. SO2 + 2H2= S + 2H2O