5. When water is electrolysed, hydrogen and oxygen wereobtained which

1.	5. When water is electrolysed, hydrogen and oxygen wereobtained which were collccted and found to be 16.8litres at STP. Then, the weight of water electrolysed is(1) 18 g 2) 36g 3) 9g (4) 45 g
Answer» The volume of H2 and O2 , will be in ratio 2:1 so, volume of H2 = 2/3(16.8 = 11.2L moles of H2 = 11.2/22.4 = 0.5 moles now in the reaction , moles of H2 is same as that of the moles of H2O electrolysed so, moles of H2O = 0.5 and mass = 0.518 = 9g but how can calculate the volume of hydrogen? in 1 mole the volume of any gas is 22.4L and hydrogen's volume is two third of 16.8L = 11.2Lfrom the reaction H2O → H2 +1/2O2 so if ,22.4L is one mole.. then 11.2 L will be ??

5. When water is electrolysed, hydrogen and oxygen wereobtained which were collccted and found to be 16.8litres at STP. Then, the weight of water electrolysed is(1) 18 g 2) 36g 3) 9g (4) 45 g

Answer»

The volume of H2 and O2 , will be in ratio 2:1

so, volume of H2 = 2/3*(16.8 = 11.2L

moles of H2 = 11.2/22.4 = 0.5 moles

now in the reaction , moles of H2 is same as that of the moles of H2O electrolysed

so, moles of H2O = 0.5 and mass = 0.5*18 = 9g

but how can calculate the volume of hydrogen?

in 1 mole the volume of any gas is 22.4L

and hydrogen's volume is two third of 16.8L = 11.2Lfrom the reaction H2O → H2 +1/2O2

so if ,22.4L is one mole.. then 11.2 L will be ??