Question

The molality of solution containing 20% mass of ethanol (C6H5OH, Mr = 46 gram/mole) is.......molal...

please jwb soal kimia aku :') materi uts

Answer 1

20% ethanol berarti pelarut nya 80%, kita ambil contoh itu larutan 100 gr berarti ethanol nya 20gr, tinggal di hitung pakai rumus n= m/Mr
n= 20/46= 0.434 mol

Answer 2

dik : m ( etanol) = 20 gr ( 100-20=80)
jadi , massa C₆H₅OH = 80

dit : m ...?

m = massa / Mr x 1000/P
     = 20 / 46 X 1000 / 80
     = 0,43 / 12,5
     = 0.0344