Jawaban:

Menentukan kalor reaksi

table attributes columnalign right center left columnspacing 0px end attributes row cell italic q subscript reaksi end cell equals cell negative sign left parenthesis italic q subscript larutan plus italic q subscript kalorimeter right parenthesis end cell row blank equals cell negative sign left parenthesis m cross times c cross times increment T and C cross times increment T right parenthesis end cell row blank equals cell negative sign left parenthesis 500 space g cross times 4 comma 18 space J space g to the power of negative sign 1 end exponent degree C to the power of negative sign 1 end exponent cross times left parenthesis 43 comma 7 minus sign 30 right parenthesis degree C right parenthesis end cell row blank equals cell negative sign 28.633 space J end cell row blank equals cell negative sign 28 comma 633 space kJ end cell end table

*Kapasitas kalor kalorimeter pada soal diabaikan, sehingga yang terlibat hanya italic q subscript larutan

menentukan mol butana

table attributes columnalign right center left columnspacing 0px end attributes row mol equals cell massa over Mr end cell row cell mol space C subscript 4 H subscript 10 end cell equals cell fraction numerator massa space C subscript 4 H subscript 10 over denominator M subscript r space C subscript 4 H subscript 10 end fraction end cell row blank equals cell fraction numerator 0 comma 58 space g over denominator 58 space g forward slash mol end fraction end cell row blank equals cell 0 comma 01 space mol end cell end table

Menentukan entalpi pembakaran butana

table attributes columnalign right center left columnspacing 0px end attributes row cell increment H end cell equals cell italic q subscript reaksi over mol end cell row blank equals cell fraction numerator negative sign 28 comma 633 space kJ over denominator 0 comma 01 space mol end fraction end cell row blank equals cell negative sign 2.863 comma 3 space kJ forward slash mol end cell end table

Jadi, perubahan entalpi pembakaran butana sebesar -2.863,3 kJ/mol.