From 392 mg of H 2 SO 4, 1.204 × 1021 molecules are removed. How many moles of H 2 SO 4 are left?

Question

From 392 mg of H 2 SO 4, 1.204 × 1021 molecules are removed. How many moles of H 2 SO 4 are left? (A) 2.0 × 10-3 (B) 1.2 × 10-3 (C) 4.0 × 10-3 (D) 1.5 × 10-3

Tardigrade Admin · Accepted Answer

392 mg =392 / 1000 g No. of moles of H 2 SO 4=(0.392/98)=0.004 As N=n NA ∴ n=(N/NA)=(1.204 × 1021 text molecules /6.023 × 1023 text molecules )=0.002 moles No. of moles of H 2 SO 4 left =0.004-0.002 =0.002=2.0 × 10-3

Q. From $392 m g$ of $H_{2} S O_{4}, 1.204 \times 1 0^{21}$ molecules are removed. How many moles of $H_{2} S O_{4}$ are left?

$2.0 \times 1 0^{- 3}$

$1.2 \times 1 0^{- 3}$

$4.0 \times 1 0^{- 3}$

$1.5 \times 1 0^{- 3}$

Q. From 392mg of H2​SO4​,1.204×1021 molecules are removed. How many moles of H2​SO4​ are left?

2.0×10−3

1.2×10−3

4.0×10−3

1.5×10−3

392mg=392/1000g No. of moles of H2​SO4​=980.392​=0.004 As N=nNA​ ∴n=NA​N​=6.023×1023 molecules 1.204×1021 molecules ​=0.002 moles No. of moles of H2​SO4​ left =0.004−0.002 =0.002=2.0×10−3

Q. From $392 m g$ of $H_{2} S O_{4}, 1.204 \times 1 0^{21}$ molecules are removed. How many moles of $H_{2} S O_{4}$ are left?

$2.0 \times 1 0^{- 3}$

$1.2 \times 1 0^{- 3}$

$4.0 \times 1 0^{- 3}$

$1.5 \times 1 0^{- 3}$