Question

If you are using 3.00% (mass/mass) hydrogen peroxide solution and you determine that the mass of solution required to reach the equivalence point is 5.125 g, how many moles of hydrogen peroxide molecules are present?

Answer 1

According to the given data

each 100gms of solution has 3gms of H₂O₂

then 5.125gms of solution has----------------------? gms of H₂O₂

_{$mass of H_{2}O_{2}=\frac{5.125X3}{100}=0.153gms$}

$molar \; mass of H_{2}O_{2}=34gms$

hence

$no. of \: moles \: of \; H_{2}O_{2}=\frac{mass}{molarmass}= \frac{0.153}{34}=0.0045moles$

$\therefore no. of \: moles \: of \; H_{2}O_{2}=0.0045moles$