If you have 23 g of Lithium oxide, what is the volume of Oxygen that is produced? Li2O2 + H2O  LiOH + O2

1st step : find the number of moles for the known substance

number of moles =mass/ relative molecular mass

n=23/Li2O2

n=23/(14+32)

n =23/46

n= 0,5moles

2nd step : balance the equation

2Li202 +2H20> 4LiOH +O2

3rd step : find the mole ratio of the known or stated using the balanced equation

Li2O2 : O2

2 : 1

4th step :find the number of moles for the asked using the mole ratio using simple proportion

Li2O2 :O2

2 :1

0,5 :???

0,5/2 ×1

= 0,25moles for (O2)

5th step : find the asked either mass , volume , concentration

number of moles = volume/molar gas volume

volume = number of moles × molar gas volume

v = 0,25moles × 28dm^3

v= 7 dm^3 of (O2)

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.