Hitunglah harga pH larutan 0,1 M dan 0,1 M jika diketahui dan ! Jika kedua larutan dengan volume yang sama direaksikan, tentukan harga pH larutan campuran!

Hitunglah harga pH larutan 0,1 M $begin mathsize 14px style N H subscript 4 O H end style$ dan 0,1 M $begin mathsize 14px style H C N end style$ jika diketahui $begin mathsize 14px style K subscript a space H C N equals 1 cross times 10 to the power of negative sign 4 end exponent end style$ dan $begin mathsize 14px style K subscript b space N H subscript 4 O H equals 1 cross times 10 to the power of negative sign 5 end exponent end style$ ! Jika kedua larutan dengan volume yang sama direaksikan, tentukan harga pH larutan campuran!

Jawaban:

Menentukan pH $begin mathsize 14px style N H subscript 4 O H end style$

$begin mathsize 14px style N H subscript 4 O H end style$ bersifat basa lemah

$table attributes columnalign right center left columnspacing 0px end attributes row cell open square brackets O H to the power of minus sign close square brackets end cell equals cell space square root of K subscript b cross times Mb end root end cell row blank equals cell space square root of 1 cross times 10 to the power of negative sign 5 end exponent space cross times space 0 comma 1 end root end cell row blank equals cell square root of 1 cross times 10 to the power of negative sign 6 end exponent end root end cell row blank equals cell 1 cross times 10 to the power of negative sign 3 end exponent end cell end table$

$table attributes columnalign right center left columnspacing 0px end attributes row cell pOH space end cell equals cell space minus sign space log space open square brackets O H to the power of minus sign close square brackets end cell row blank equals cell space minus sign space log space 1 cross times 10 to the power of negative sign 3 end exponent end cell row blank equals cell space 3 end cell end table$

$table attributes columnalign right center left columnspacing 0px end attributes row cell pH space end cell equals cell space 14 space minus sign space pOH end cell row blank equals cell space 14 space minus sign space 3 end cell row blank equals 11 end table$

Menentukan pH dari HCN

$table attributes columnalign right center left columnspacing 0px end attributes row cell open square brackets H to the power of plus sign close square brackets end cell equals cell space square root of K subscript a cross times Ma end root end cell row blank equals cell space square root of 1 cross times 10 to the power of negative sign 4 end exponent cross times 0 comma 1 end root end cell row blank equals cell space square root of 1 cross times 10 to the power of negative sign 5 end exponent end root end cell row blank equals cell space 3 comma 16 cross times 10 to the power of negative sign 3 end exponent end cell end table$

$table attributes columnalign right center left columnspacing 0px end attributes row cell pH space end cell equals cell space minus sign space log space open square brackets H to the power of plus sign close square brackets end cell row blank equals cell space minus sign space log space 3 comma 16 cross times 10 to the power of negative sign 3 end exponent end cell row blank equals cell space 3 space minus sign space log space 3 comma 16 end cell end table$

Menentukan pH dari larutan campuran

Jika kedua larutan dicampurkan dengan konsentrasi dan volume sama, maka akan menghasilkan larutan garam yang terhidrolisis total (berasal dari asam lemah dan basa lemah). Karena nilai $begin mathsize 14px style K subscript a greater than K subscript b end style$ , maka garam ini bersifat asam, Sehingga, pH campurannya adalah:

$table attributes columnalign right center left columnspacing 0px end attributes row cell open square brackets H to the power of plus sign close square brackets end cell equals cell square root of K subscript w over K subscript b cross times K subscript a end root end cell row blank equals cell square root of 10 to the power of negative sign 14 end exponent over 10 to the power of negative sign 5 end exponent cross times 10 to the power of negative sign 4 end exponent end root end cell row blank equals cell square root of 10 to the power of negative sign 13 end exponent end root end cell row blank equals cell 10 to the power of negative sign 6 comma 5 end exponent end cell end table$

$table attributes columnalign right center left columnspacing 0px end attributes row cell pH space end cell equals cell space minus sign space log space open square brackets H to the power of plus sign close square brackets end cell row blank equals cell space minus sign space log space 10 to the power of negative sign 6 comma 5 end exponent end cell row blank equals cell space 6 comma 5 end cell end table$

Jadi, pH dari $begin mathsize 14px style N H subscript 4 O H end style$ adalah 11, pH dari HCN adalah $Error converting from MathML to accessible text.$ , dan pH campuran larutannya adalah 6,5.

Ruangguru

RUANGGURU HQ

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

Coba GRATIS Aplikasi Ruangguru

Download di Google Play

Download di Appstore

Produk Ruangguru

Produk Lainnya

Bantuan & Panduan

Hubungi Kami

081578200000

[email protected]

02140008000

Ikuti Kami

Instagram

Facebook

Twitter

Youtube