PEMBAHASAN SOAL OSNG TINGKAT PROVINSI TAHUN 2014

Jawaban:

Reaksi pembakaran:

aCxHy + bO2 cCO2 + dH2O

Penentuan mol:

,mol CO2 =

. = 0,0821136363636 = c

,mol H2O =

. = 0,0616111111111 = d

Sesuai persamaan reaksi, maka: ax = c;

Penentuan Mr:

=

ay = 2d;

=

=

x(

)

= 0,0053115657658 = a(, x )

,Mr CxHy = , = 54,2212998386217 Penentuan Rumus Empiris:

=

=, , = 15,4594031184386

=

=

x,, = 23,1988508954555

x : y = 15,4594031184386 : 23,1988508954555 = 1 : 1,5006304394628 = 2 : 3 Rumus Empiris = (C2H3)

Penentuan Rumus Molekul:

(RE)n = RM (C2H3)n = 54,2213 (212) + (3 1)n = 54,2213 (24 + 3)n = 54,2213

n = ,

= 2,0081962962963 2

Jadi rumus molekul hidrokarbon tersebut adalah C4H6