Question

20 ml of sample of h2o2 gives 400ml of oxygen at NTP.the volume strength of sample is

Answer 1

Here you go....

This means that 1 volume of H2O2 will give off 28 volumes of O2 at NTP,20C and at 1atm

So, 1Litre of solution can produce 28 litre of oxygen under these conditions

let us assume that oxygen is a perfect gas,then from

PV = nRT ,where P = 1atm and V = 28L

so that we can calculate the n,ie number of moles of O2

n = PV/RT

n = 1X28/0.0821 X 298.15

n = 1.144 moles of O2

hydrogen peroxide decomposes as 2H2O2 ------------>2H2O + O2

Since twice the number of moles are required to produce 1 mole of oxygen so to generate 1.144 moles of O2 in 1L of solution,there must be 2.28 moles of H2O2 present in 1Litre

So molarity of H2O2 is 2.28

now to calculate molality

molality = molarity X density

= 2.28 X 26.5

= 60.42g/L

So malality = 60.42g/l