Roboguru

Pada titrasi 50 mL  0,1 M (Ka ) dengan  0,1 M. Tentukan nilai pH larutan setelah penambahan  sebesar: 0 mL 25 mL 50 mL 75 mL

Pertanyaan

Pada titrasi 50 mL begin mathsize 14px style C H subscript 3 C O O H end style 0,1 M (Ka begin mathsize 14px style C H subscript 3 C O O H equals space 1 comma 8 cross times 10 to the power of negative sign 5 end exponent end style) dengan begin mathsize 14px style Na O H end style 0,1 M. Tentukan nilai pH larutan setelah penambahan begin mathsize 14px style Na O H end style sebesar:

  1. 0 mL
  2. 25 mL
  3. 50 mL
  4. 75 mL

Pembahasan Soal:

1. Pada saat penambahan 0 mL begin mathsize 14px style Na O H end style 0,1 M.

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 end cell equals cell square root of Ka cross times M end root end cell row blank equals cell square root of 1 comma 8 cross times 10 to the power of negative sign 5 end exponent cross times 10 to the power of negative sign 1 end exponent end root end cell row blank equals cell square root of 1 comma 8 cross times 10 to the power of negative sign 6 end exponent end root end cell row blank equals cell 1 comma 34 cross times 10 to the power of negative sign 3 end exponent space M end cell end table end style


begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row pH equals cell negative sign log space 1 comma 34 cross times 10 to the power of negative sign 3 end exponent end cell row blank equals cell 3 minus sign log space 1 comma 34 end cell end table end style


2. Pada saat penambahan 25 mL begin mathsize 14px style Na O H end style 0,1 M.


begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell mmol space C H subscript 3 C O O H end cell equals cell M cross times V end cell row blank equals cell 0 comma 1 cross times 50 end cell row blank equals cell 5 space mmol end cell end table end style


begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell mmol space Na O H end cell equals cell M cross times V end cell row blank equals cell 0 comma 1 cross times 25 end cell row blank equals cell 2 comma 5 space mmol end cell end table end style


Persamaan reaksinya:




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 end cell equals cell Ka cross times begin inline style a over g end style end cell row blank equals cell 1 comma 8 cross times 10 to the power of negative sign 5 end exponent cross times begin inline style fraction numerator 2 comma 5 over denominator 2 comma 5 end fraction end style end cell row blank equals cell 1 comma 8 cross times 10 to the power of negative sign 5 end exponent space M end cell end table end style


begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row pH equals cell negative sign log space open square brackets H to the power of plus sign close square brackets end cell row blank equals cell negative sign log space 1 comma 8 cross times 10 to the power of negative sign 5 end exponent end cell row blank equals cell 5 minus sign log space 1 comma 8 end cell end table end style


3. Pada saat penambahan 50 mL begin mathsize 14px style Na O H end style 0,1 M.


begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell mmol space Na O H end cell equals cell M cross times V end cell row blank equals cell 0 comma 1 cross times 50 end cell row blank equals cell 5 space mmol 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 C H subscript 3 C O O Na close square brackets end cell equals cell begin inline style fraction numerator mmol over denominator V space total end fraction end style end cell row blank equals cell begin inline style fraction numerator 5 space mmol over denominator 100 space mL end fraction end style end cell row blank equals cell 5 cross times 10 to the power of negative sign 2 end exponent space M 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 O H to the power of minus sign close square brackets end cell equals cell square root of begin inline style Kw over Ka end style cross times open square brackets G close square brackets end root end cell row blank equals cell square root of begin inline style fraction numerator 10 to the power of negative sign 14 end exponent over denominator 1 comma 8 cross times 10 to the power of negative sign 5 end exponent end fraction cross times 5 cross times 10 to the power of negative sign 2 end exponent end style end root end cell row blank equals cell square root of 27 comma 78 cross times 10 to the power of negative sign 10 end exponent end root end cell row blank equals cell 5 comma 27 cross times 10 to the power of negative sign 5 end exponent space M end cell end table end style


begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row pOH equals cell negative sign log space open square brackets O H to the power of minus sign close square brackets end cell row blank equals cell negative sign log space 5 comma 27 cross times 10 to the power of negative sign 5 end exponent end cell row blank equals cell 5 minus sign log space 5 comma 27 end cell end table end style


begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row pH equals cell 14 minus sign pOH end cell row blank equals cell 14 minus sign left parenthesis 5 minus sign log space 5 comma 27 right parenthesis end cell row blank equals cell 9 plus log space 5 comma 27 end cell end table end style

 

3. Pada saat penambahan 75 mL begin mathsize 14px style Na O H end style 0,1 M.


begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row cell mmol space Na O H end cell equals cell M cross times V end cell row blank equals cell 0 comma 1 cross times 75 end cell row blank equals cell 7 comma 5 space mmol 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 Na O H close square brackets end cell equals cell begin inline style fraction numerator mmol space sisa over denominator V space total end fraction end style end cell row blank equals cell begin inline style fraction numerator 2 comma 5 space mmol over denominator 125 space mL end fraction end style end cell row blank equals cell 0 comma 02 space M 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 O H to the power of minus sign close square brackets end cell equals cell n cross times M end cell row blank equals cell 1 cross times 2 cross times 10 to the power of negative sign 2 end exponent space M end cell row blank equals cell 2 cross times 10 to the power of negative sign 2 end exponent space M end cell end table end style


begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row pOH equals cell negative sign log space open square brackets O H to the power of minus sign close square brackets end cell row blank equals cell negative sign log space 2 cross times 10 to the power of negative sign 2 end exponent end cell row blank equals cell 2 minus sign log space 2 end cell end table end style


begin mathsize 14px style table attributes columnalign right center left columnspacing 0px end attributes row pH equals cell 14 minus sign left parenthesis 2 minus sign log space 2 right parenthesis end cell row blank equals cell 12 plus log space 2 end cell end table end style

Pembahasan terverifikasi oleh Roboguru

Terakhir diupdate 03 April 2021

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