Question

How many atoms of hydrogen are in 210 g of hydrogen peroxide (h2o2)?

Answer 1

Molar mass:

$1 \ mol \ H_2O_2 = 34.0147 \ g \ H_2O_2$

Grams to moles:

$(210 \ g \ H_2O_2) * ( \frac{1 \ mol \ H_2O_2 }{34.0147 \ g \ H_2O_2}) = 6.17 \ mol \ H_2O_2$

Moles to atoms (Avogadro's number):
$1 \ mol = 6.022 * 10^{22} \ particles$
$(6.17 \ mol \ H_2O_2) * (\frac{6.022 * 10^{22} \ molecules \ H_2O_2}{1 \ mol \ H_2O_2}) * ( \frac{2 \ atoms \ H}{molecule \ H_2O_2})$

Answer:
$= 7.43 * 10^{23} \ H \ atoms$

Answer 2

Answer:

Number of hydrogen atoms =  $7.44\times 10^{24}$

Explanation:

Given,

Mass of $H_2O_2$ = 210 g

Molar mass of $H_2O_2$ = 34.0147 g/mol

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$Moles= \frac{210\ g}{34.0147\ g/mol}$

$Moles_{H_2O_2}= 6.1738\ mol$

From the formula of $H_2O_2$,

1 mole of $H_2O_2$ contains 2 moles of hydrogen atoms

6.1738 moles of $H_2O_2$ contains 2*6.1738 moles of hydrogen atoms

Moles of hydrogen = 12.3476 mole

Avogadro constant:-  $N_a=6.023\times 10^{23}\ mol^{-1}$

1 mole contains $6.023\times 10^{23}$ atoms

12.3476 moles contains $12.3476\times 6.023\times 10^{23}$ atoms

Number of hydrogen atoms =  $7.44\times 10^{24}$