Roboguru

Didalam 1 liter larutan penyangga yang mengandung 0,1 M dan 0,1 M ditambah 10 mL larutan HCl 0,1 M. Jika . Hitung pH larutan penyangga tersebut sebelum dan sesudah ditambah HCl

Didalam 1 liter larutan penyangga yang mengandung 0,1 M begin mathsize 14px style C H subscript 3 C O O H end style dan 0,1 M begin mathsize 14px style C H subscript 3 C O O H to the power of minus sign end style ditambah 10 mL larutan HCl 0,1 M. Jika begin mathsize 14px style K subscript a space C H subscript 3 C O O H equals 10 to the power of negative sign 5 end exponent end style. Hitung pH larutan penyangga tersebut sebelum dan sesudah ditambah HCl

Jawaban:

pH larutan penyangga sebelum penambahan HCl

Menentukan nilai mol larutan

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell n subscript C H subscript 3 C O O H end subscript space end cell equals cell space M cross times V end cell row blank equals cell space 0 comma 1 cross times 1 end cell row blank equals cell space 0 comma 1 space mol end cell end table end style 

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell n subscript C H subscript 3 C O O to the power of minus sign end subscript space end cell equals cell space M cross times V end cell row blank equals cell space 0 comma 1 cross times 1 end cell row blank equals cell space 0 comma 1 space mol end cell end table end style 

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell open square brackets H to the power of plus sign close square brackets space end cell equals cell space K subscript a cross times n subscript C H subscript 3 C O O H end subscript over n subscript C H subscript 3 C O O to the power of minus sign end subscript end cell row blank equals cell space 10 to the power of negative sign 5 end exponent cross times fraction numerator 0 comma 1 over denominator 0 comma 1 end fraction end cell row blank equals cell space 10 to the power of negative sign 5 end exponent end cell end table end style  

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell italic p H space end cell equals cell space minus sign space log space open square brackets H to the power of plus sign close square brackets end cell row blank equals cell space minus sign space log space 10 to the power of negative sign 5 end exponent end cell row blank equals cell space 5 end cell end table end style  

pH larutan penyangga sesudah penambahan HCl

Menentukan nilai mol larutan 

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell n subscript HCl space end cell equals cell space M cross times V end cell row blank equals cell space 0 comma 1 cross times 0 comma 01 end cell row blank equals cell space 0 comma 001 space mol end cell end table end style 

HCl merupakan asam kuat bervalensi satu, sehingga nilai mol begin mathsize 14px style H to the power of plus sign end style:

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell n subscript H to the power of plus sign end subscript space end cell equals cell space n subscript HCl cross times valensi end cell row blank equals cell space 0 comma 001 cross times 1 end cell row blank equals cell space 0 comma 001 space mol end cell end table end style 

Penambahan HCl akan menambahkan ion begin mathsize 14px style H to the power of plus sign end style  dan bereaksi dengan basa konjugasi begin mathsize 14px style C H subscript 3 C O O to the power of minus sign end style, reaksi yang terjadi:

 

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell open square brackets H to the power of plus sign close square brackets space end cell equals cell space K subscript a cross times n subscript C H subscript 3 C O O H end subscript over n subscript C H subscript 3 C O O to the power of minus sign end subscript end cell row blank equals cell space 10 to the power of negative sign 5 end exponent cross times fraction numerator 0 comma 001 over denominator 0 comma 099 end fraction end cell row blank equals cell space 0 comma 01 cross times 10 to the power of negative sign 5 end exponent end cell row blank equals cell space 10 to the power of negative sign 7 end exponent end cell end table end style 

begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell italic p H space end cell equals cell space minus sign space log space open square brackets H to the power of plus sign close square brackets end cell row blank equals cell space minus sign space log space 10 to the power of negative sign 7 end exponent end cell row blank equals cell space 7 end cell end table end style 

Jadi, pH larutan penyangga sebelum dan sesudah ditambah HCl adalah 5 dan 7.

0

Ruangguru

RUANGGURU HQ

Jl. Dr. Saharjo No.161, Manggarai Selatan, Tebet, Kota Jakarta Selatan, Daerah Khusus Ibukota Jakarta 12860

Coba GRATIS Aplikasi Ruangguru

Produk Ruangguru

Produk Lainnya

Hubungi Kami

Ikuti Kami

©2021 Ruangguru. All Rights Reserved