Question

How many atoms of oxygen are there in 3.65 g of H₂O₂? Show all your work (including cancelling units) for full credit.

Answer 1

Molar mass of Hydrogen peroxide (​​​​​​) = 34 g/mol

H202

Given mass of = 3.65 g

H202

No of moles of

H202

$\small =\frac {\textup{Given mass of } H_2O_2} {\textup{Molar mass of } H_2O_2}$

$\small =\frac {\textup{3.65 g} } {\textup{34 g/mol} }= \bold {0.107}\textup{ mol } H_2O_2$

We know that one mole of any substance contain avagadro's number of particles. Avagadro's no = $\small 6.022*10^{23}$ . So 1 mol of
H202
contain $\small 6.022*10^{23}$ number of
H202
molecules.

23 1 mol = 6:00 ax 10 moleculer 29 6.022x10 We have 0 • 107 mol of H₂O₂. So no. of molecules of 0.107 mol H₂Oe 0.10 7 moes Ho fmote the 6.44*10 moleates of H₂O2 molecules of the 22 H2O2 9o made up of 2 atome of oxygen 2 atoms of hydrogens. atomi. and . No. of atoons of oneygen estants Sample 2.2 2 akoma 6. 2044810 molecules -HO X of o i molecules H 2 23 1.29 x 10 alome of o

No of atoms of O in 3.65 g H2O2 = $\small 1.29*10^{23}$ atoms