Sebanyak 3,01 x 10^22 molekul senyawa A2B3 massa 8 gram, jika Ar.A = 20, maka Ar.B?

A.30
B. 40
C. 60
D. 120

Sebanyak 3,01 x 10^22 molekul senyawa A2B3 massa 8 gram, jika Ar.A = 20, maka Ar.B?

Jawaban Terkonfirmasi

Mata Pelajaran : Kimia
Materi : Stokiometri

Gambar Jawaban

A2B3:
x (jmlh molekul) = 3,01 × 10²² molekul
m (massa) = 8 gram
Ar A = 20
Ar B = ?
l (bilangan Avogrado) = 6,02 × 10²³ molekul/mol

n = x/l
$= frac{3.01 times {10}^{22} }{6.02 times {10}^{23} } \ = 0.5 times {10}^{22 - 23} \ = 0.5 times {10}^{ - 1} = 0.05 : mol$

Mr A2B3 = m/n
= 8/0,05 = 160 gram/mol

Mr A2B3 = 2(Ar A) + 3(Ar B)
160 = 2(20) + 3(Ar B)
160 = 40 + 3Ar B
160 – 40 = 3Ar B
120 = 3Ar B
Ar B = 120/3 = 40 (B)

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