Mr(Na2CO3) = 23*2 + 12 + 16*3 = 106
W(C) = Ar(C) * n / Mr(Na2CO3) *100% = 12 / 106 *100% = 11,3%
Ответ: 1)
30 а.е.м. (г/моль).........
5.75г 2,8л
2Me+2H2O=2MeOH+H2
2х 22,4л
х=5,75*22,4/2,8*2=23 натрий
Ar(Na)=23
Na2CO3+H2O<=>NaHCO3 +NaOH
CuCl+H2O <=> CuOHCl+HCl
Al2S3+6H2O<=>2Al(OH)3+3H2S