Ответ:
дано
m(ppa NaOH) = 250 g
m(H2SO4) = 17.6 g
--------------------------
W(NaOH) -?
2NaOH+H2SO4-->Na2SO4+H2O
M(H2SO4) = 98 g/mol
n(H2SO4) = m/M = 17.6 / 98 = 0.18 mol
2n(NaOH) = n(H2SO4)
n(NaOH) = 2*0.18 / 1 = 0.36 mol
M(NaOH) = 40 g/mol
m(NaOH) = n*M = 0.36 * 40 = 14.4 g
W(NaOH) = m(NaOH) / m(ppa NaOH) * 100% = 14.4 / 250 * 100% = 5.76%
ответ 5.76%
Объяснение:
1) 2Ca+02→2CaO
2) CaO+H2O→Ca(OH)2
3)Ca(OH)2+2HNO3→Ca(NO3)2+2H20
Раствор.
M =0,42×16+0,28×2+0,3×44=20,48
Плотность по водороду = 20.48/2=10,24