The capacity for doing work is Energy.
Answer: Covalent bonds usually occur between nonmetals. In Covalent bond elements share their electrons.
The balanced equation for the above reaction is as follows;
2Ca + O₂ ---> 2CaO
stoichiometry of Ca to O₂ is 2:1
we first need to find the limiting reactant
number of Ca moles - 6.84 mol
number of O₂ moles - 4.00 mol
if Ca is the limiting reactant
if 2 mol of Ca reacts with 1 mol of O₂
then 6.84 mol of Ca reacts with - 6.84 / 2 = 3.42 mol of O₂
this means that Ca is the limiting reactant and O₂ is in excess
therefore amount of CaO produced depends on amount of limiting reactant present
stoichiometry of Ca to CaO is 2:2
number of moles of Ca reacted = number of CaO moles formed
number of moles of CaO formed - 6.84 mol
answer is 6.84 mol