Question

from 392 mg of h2so4 1.204 × 10^21 molecules are removed .how many moles of h2so4 are left??????

Answer 1

Answer:

2.0×10^-3 moles are left

Answer 2

Answer:

$\bold{2.0 \times 10^{-23}}$ moles of  [tex]\bold{H_{2} S O_{4}}[/tex] is left.

Explanation:

The Mass of $\mathrm{H}_{2} \mathrm{SO}_{4}$ = 392 mg = 0.392 g

The Molecular mass of  $H_{2} S O_{4}$ = 98 g

Number of moles of  $\mathrm{H}_{2} \mathrm{SO}_{4}=\frac{\text {Mass}_{-} \text { of }-H_{2} S O_{4}}{\text {Molar}_{-} \text { mass }_{-} \text { of }_{-} H_{2} S O_{4}}=\frac{0.392}{98}=0.004$

Number of molecules removed from the solution

Here, n = number of moles

N = number of molecules

      $\mathrm{No}$ = Avogadro’s Number

n =  $=\frac{N}{N_{o}}=\frac{1.204 \times 10^{21}}{6.02 \times 10^{23}}=0.002$

Number of moles of $\mathrm{H}_{2} \mathrm{SO}_{4}$ left = 0.004 – 0.002 = $2.0 \times 10^{-23}$

Therefore, the number of moles of $H_{2} S O_{4}$ left after removal of 392 g of $H_{2} S O_{4}$ = $2.0 \times 10^{-23}$