Jika 100 mL larutan H2SO4 0,1 M direaksikan dengan 400 mL NH3 0,05 M (Kb NH3 = 2 x 10-5), pH campuran adalah ....

Pertanyaan

Jika 100 mL larutan H₂SO₄ 0,1 M direaksikan dengan 400 mL NH₃ 0,05 M (K_b NH₃ = 2 x 10^-5), pH campuran adalah .... $\;$

5,5 - log 2
9
8,5
5
4

S. Lubis

Master Teacher

Jawaban terverifikasi

Jawaban

maka jawaban yang tepat adalah 5,4.

Pembahasan

$n subscript H subscript 2 S O subscript 4 end subscript equals 0 comma 1 cross times 100 equals 10 space mmol n subscript N H subscript 3 end subscript equals 0 comma 05 cross times 400 equals 20 space mmol space space space space H subscript 2 S O subscript 4 and 2 N H subscript 3 yields open parentheses N H subscript 4 close parentheses subscript 2 S O subscript 4 m space space space 10 space space space space space space space space space 20 bottom enclose r space space space space space minus sign 10 space space space space space minus sign 20 space space space space space space space plus 10 end enclose s space space space space 0 space space space space space space space space space space space 0 space space space space space space space space space space space space space space 10 n subscript N H subscript 4 to the power of plus end subscript equals 2 cross times n subscript open parentheses N H subscript 4 close parentheses subscript 2 S O subscript 4 end subscript n subscript N H subscript 4 to the power of plus end subscript equals 20 space mmol open square brackets N H subscript 4 to the power of plus close square brackets equals bevelled 20 over 500 equals 0 comma 04 space M N H subscript 4 to the power of plus plus H subscript 2 O equilibrium N H subscript 3 and H subscript 3 O to the power of plus sign open square brackets H to the power of plus sign close square brackets equals square root of K subscript w over K subscript b cross times open square brackets N H subscript 4 to the power of plus close square brackets end root open square brackets H to the power of plus sign close square brackets equals square root of fraction numerator 10 to the power of negative sign 14 end exponent over denominator 2 cross times 10 to the power of negative sign 5 end exponent end fraction cross times 0 comma 04 end root open square brackets H to the power of plus sign close square brackets equals 4 comma 5 cross times 10 to the power of negative sign 6 end exponent pH equals minus sign log space open parentheses 4 comma 5 cross times 10 to the power of negative sign 6 end exponent close parentheses pH equals 5 comma 4 space$

Dengan demikian, maka jawaban yang tepat adalah 5,4.

2rb+

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