Массовую долю серы: а) na2so4 mr (na2so4) = w(s) = б) soз mr (soз) = w (s) = в) cus mr (cus) = w(s) = г) h2soз mr (na2soз) w (s) =

А)М(Na2SO4)=23*2+32*1+16*4=142
W(S)32:142*100%=22%
б)M(SO3)32*1+16*3=80
W(S)= 32:80*100%=40%
в)M(CuS)=64*1+32*1=96
W(S)=32:96*100%=33%
г)M(H2SO4)1*2+32*1+16*3=82
W(S)32:82*100%=39%