Question

Assuming the density of 3% h2o2 is 1.00g/ml, what mass of h2o2 is in a 1.00ml sample? how many moles is this ?

Answer 1

Density conversion: 1.00g/ml * 1.00ml = 1.00g h2o2.  
Molar mass of H2O2 is 34.01468 g/mol ((1.00794 g/mol of H * 2) + (15.9994 g/mol of O * 2))  
Dividing 1.00g of H2O2 by its molar mass leads to 2.94x10^-2 mols with respect to significant figures.

Answer 2

Answer:

Mass of H2O2 = 0.03 g

Moles of H2O2 is 8.82*10^4 (approximately 9.0*10^-4 moles)

Explanation:

Given:

Concentration of H2O2 = 3%

Volume = 1.00 ml

Density = 1.00 g/ml

To determine:

Mass and moles of H2O2 in the given sample

Calculation:

$%H2O2 = \frac{grams\ H2O2}{100\ ml sample}$

Here, 3% H2O2 implies that there is 3 g H2O2 in 100 ml of sample

Therefore, amount of H2O2 in 1.00 ml sample would be:

$=\frac{3\ g\ H2O2*1.00\ ml}{100\ ml} =0.03\ g$

Molecular weight of H2O2 = 34.01 g/mol

$Moles\ H2O2 =\frac{Mass}{Mol.wt} =\frac{0.03}{34.01} =8.82*10^{-4} moles$